KR102020951B1 - Apparatus and method for controlling engine in stating of hybrid vehicle - Google Patents

Abstract

An engine control apparatus and method are provided when starting a hybrid vehicle. The engine control apparatus at the start of the hybrid vehicle according to the embodiment of the present invention collects state information of the ignition switch, the coolant temperature sensor, the high voltage battery, the low voltage battery, and the accelerator pedal position sensor, and after the vehicle is started, the engine temperature is increased. A determination unit that determines whether the first threshold value is less than the first threshold value, and determines whether the BSG operating condition is satisfied; And a torque calculating unit which collects the required rotational speed, the current rotational speed, and the pulley ratio of the engine, calculates the BSG torque for assisting the torque of the engine, and generates the calculated BSG torque to increase the rotational speed of the engine. It includes;

Description

Apparatus and method for controlling engine in stating of hybrid vehicle for starting hybrid vehicle

The present invention relates to cold start of a hybrid vehicle, and more particularly, to an engine control apparatus and a method for starting a hybrid vehicle that can reduce the fuel consumption by raising the temperature of the engine by assisting the engine torque during cold start.

In general, the internal combustion engine combustion activity during cold-start is one of the most fuel-consuming sections per unit time.

At this time, it is necessary to raise the temperature of the engine in order to reduce fuel consumption. For this purpose, immediately after cold start, the engine maintains the engine speed above a certain level for a certain time.

That is, by keeping the engine speed above a certain level and rapidly raising the temperature in the engine internal combustion engine, it is possible to quickly exit the cold start section, thus reducing fuel consumption.

At this time, the idle time of the idle engine speed, that is, the engine speed maintained in a state where the accelerator pedal is not depressed, is maintained at a predetermined level, but the maintenance time is approximately 10 to 120 seconds depending on the vehicle state and the outside temperature.

However, while maintaining the high engine speed, the temperature inside the engine rises, but since it is made only by the movement of the engine, the fuel consumption for maintaining the engine speed is much higher than the fuel consumption immediately after the hot start. As a result, such fuel consumption lowers vehicle fuel economy.

KR 10-0792922 B

In order to solve the problems of the prior art as described above, an embodiment of the present invention provides an engine control apparatus and method for starting a hybrid vehicle that can maintain a high engine speed by assisting the torque of the engine using the BSG. I would like to.

According to an aspect of the present invention for solving the above problems, collecting the state information of the ignition switch, the coolant temperature sensor, the high voltage battery, the low voltage battery, and the accelerator pedal position sensor, the temperature of the engine after the vehicle is started A determination unit that determines whether or not the first threshold value is less than or equal to the operating condition of the BSG when the temperature of the engine is less than the first threshold value; And collect the required rotational speed, the current rotational speed and the pulley ratio of the engine, calculate a BSG torque for assisting the torque of the engine, and calculate the calculated BSG torque to increase the rotational speed of the engine. The engine control device is provided at the start of the hybrid vehicle comprising a torque calculating unit for generating.

In an example embodiment, the determination unit may include a first condition in which the temperature of the engine is less than the first threshold value, a second condition without an operation history of the accelerator pedal, and a SoC of both the high voltage battery and the low voltage battery. It may be determined whether the third condition as described above and the fourth condition where the BSG is capable of normal operation are satisfied.

In one embodiment, the determination unit instructs the operation unit to perform calculation and generation of the BSG torque when all of the first to fourth conditions are satisfied, and any one of the first to fourth conditions is performed. If one is not satisfied, torque assistance of the engine by the BSG may be terminated.

In one embodiment, the operation unit may calculate the BSG torque by performing a PID control according to the difference between the requested rotational speed and the current rotational speed.

According to another aspect of the invention, the first determination step of determining whether the temperature of the engine is less than the first threshold value after the vehicle is started; A second determination step of determining whether an operating condition of a bet driven integrated starter generator (BSG) is satisfied when the temperature of the engine is equal to or less than a first threshold value; Calculating a BSG torque for assisting torque of the engine based on a required rotation speed, a current rotation speed, and a pulley ratio of the engine when the operation condition of the BSG is satisfied; Generating the calculated BSG torque to increase the number of revolutions of the engine.

In one embodiment, the engine control method when starting the hybrid vehicle may further include collecting the required number of revolutions and the current number of revolutions of the engine and the pulley ratio before the calculating step.

In an embodiment, the second determining step may include: a first step of determining whether a temperature of the engine is maintained below the first threshold value; Determining whether there is no operation history of the accelerator pedal; Determining whether both the high voltage battery and the low voltage battery SoC are greater than or equal to the second threshold value; And a fourth step of determining whether the BSG is capable of normal operation.

In one embodiment, the engine control method when starting the hybrid vehicle performs the calculating step and the generating step when all of the first step and the fourth step is satisfied in the second determination step, When any one of the first to fourth steps is not satisfied, torque assistance of the engine by the BSG may be terminated.

The calculating may include calculating the BSG torque by performing PID control according to a difference between the required rotation speed and the current rotation speed.

Engine control apparatus and method for starting a hybrid vehicle according to an embodiment of the present invention by using the BSG immediately after cold start to maintain a high engine speed by supporting the torque of the engine, thereby reducing the fuel consumption consumed immediately after cold start It can improve the fuel economy.

1 is a schematic structural diagram of a hybrid vehicle according to an embodiment of the present invention;
2 is a block diagram of an engine control apparatus at start-up of a hybrid vehicle according to an embodiment of the present invention, and
3 is a flowchart of an engine control method when starting a hybrid vehicle according to an exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like elements throughout the specification.

Hereinafter, an engine control apparatus for starting a hybrid vehicle according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. 1 is a schematic configuration diagram of a hybrid vehicle according to an embodiment of the present invention.

Referring to FIG. 1, a hybrid vehicle 1 according to an embodiment of the present invention includes an engine 10, a BSG 20, an electronic control unit 30, an inverter 40, a converter 50, a high voltage battery ( 60, the low voltage battery 70, and the electric load 80.

This hybrid vehicle 1 may be a BSG system in which the engine 10 and a motor-generator interlock through a belt, or may be a mild hybrid system using a 48V battery as a high voltage battery.

The engine 10 is interlocked with the BSG 20 through the belt 14. Here, the belt 14 may be connected between the pulley 10a connected to the rotation shaft of the engine 10 and the pulley 20a connected to the rotation shaft of the BSG 20.

The BSG 20 may function as a generator capable of generating a start motor and an alternating voltage. In detail, when the BSG 20 functions as a start motor, the BSG 20 receives a driving voltage through the inverter 40 to serve as an auxiliary power of the engine, and when the BSG 20 functions as a generator, the BSG 20 uses the high-voltage battery as the electric energy generated when the vehicle is braked. 14) can be charged.

The electronic control unit (ECU) 30 controls the components of the BSG 20, the inverter 40, the converter 50, and the like, and may include an engine control device 100 as described below. have.

Inverter 40 is a bidirectional converter that converts alternating current into direct current or direct current into alternating current, converts electrical energy supplied from high voltage battery 60 and supplies it to BSG 20, or electrical energy generated by BSG 20. By converting the high voltage battery 60 can be charged.

The high voltage battery 60 is composed of a plurality of supercapacitors, and regenerated electric energy is supplied from the BSG 20 when the vehicle is decelerated, and charged with the BSG 20 to assist engine torque when the vehicle is accelerated. Can supply In one example, the high voltage battery 60 may be a 48V battery.

The converter 50 is a DC-DC converter that converts the level of DC, and when power generation is performed, the output of the inverter 40 is changed or when the power generation is not performed, the voltage of the high voltage battery 60 is converted to a low voltage battery ( 70 may be supplied and charged, or may be supplied to the electric load (80).

The low voltage battery 70 may be supplied with electric energy converted by the converter 50 to be charged, and supply electric power charged to the electric load 80 of the hybrid vehicle 1. In one example, the low voltage battery 70 may be a 12V battery.

The electric load 80 is a variety of loads used during the operation of the hybrid vehicle 1, and may include components that consume power such as a lamp, or an electronic control function and driving means thereby. The electric load 80 may be supplied with power from the low voltage battery 70 or the high voltage battery 60 through the converter 50.

Here, the cold state is a case where the coolant temperature of the engine 10 is 50 ° C. or less, and the hot state is a case where the coolant temperature of the engine 10 is 90 to 100 ° C., and the fuel consumption according to the idle rotation of the cold state is a hot state. It is about 2 ~ 3 times higher than that.

In order to solve this problem, the hybrid vehicle 1 according to the exemplary embodiment of the present invention may increase the rotation speed of the engine 10 by assisting torque to the engine 10 using the BSG 20 under specific conditions. Thereby, the fuel consumption used for maintaining the rotation speed of the engine 10 to a predetermined level or more can be reduced.

That is, the present invention maintains the engine speed above a certain level so that the engine 10 is switched from the cold state to the hot state, thereby rapidly increasing the temperature in the engine 10, thereby eliminating the need for additional fuel consumption, thereby making the idle engine It is possible to reduce the amount of fuel required to maintain the engine speed, ie the engine speed maintained without stepping on the accelerator pedal.

2 is a block diagram of an engine control apparatus at start-up of a hybrid vehicle according to an exemplary embodiment of the present invention.

When the hybrid vehicle starts up, the engine control apparatus 100 may include a determiner 110 and a torque calculator 120.

The determination unit 110 may collect respective state information from the ignition switch 11, the coolant temperature sensor 12, the high voltage battery 60, the low voltage battery 70, and the accelerator pedal position sensor 90. Here, the determination unit 110 may determine the internal temperature of the engine 10 based on the temperature of the coolant.

In addition, the determination unit 110 may determine whether the hybrid vehicle 1 is in a cold state. In this case, the determination unit 110 may determine whether the temperature of the engine 10 is less than or equal to the first threshold Th1 after the hybrid vehicle 1 is started.

In addition, when determining that the hybrid vehicle 1 is in a cold state, the determination unit 110 may determine whether an operating condition for using the BSG 20 is satisfied. That is, the determination unit 110 may include a first condition in which the temperature of the engine 10 is maintained below the first threshold value Th1, a second condition in which the operation history of the accelerator pedal is not present, the high voltage battery 60 and the low voltage battery ( It is possible to determine whether all of the SoCs of 70) satisfy the third condition that is equal to or greater than the second threshold Th2 and the fourth condition in which the BSG 20 can operate normally.

More specifically, the determination unit 110 may determine whether the engine 10 is continuously cold based on the first condition. That is, since the present invention is for engine control during cold start of the hybrid vehicle 1, the determination unit 110 determines whether the temperature of the engine 10 is less than or equal to the first threshold value Th1 by the coolant temperature sensor 12. Can be determined.

In addition, the determination unit 110 may determine whether the engine 10 is in the idle state through the second condition. That is, since the present invention is to avoid consuming additional fuel to increase the rotation speed of the engine 10, the determination unit 110 may determine whether the accelerator pedal is used from the accelerator pedal position sensor 90.

In addition, the determination unit 110 may determine whether the state of charge of the high voltage battery 60 and the low voltage battery 70 is good through the third condition. Here, since the high voltage battery 60 provides power for the BSG 20 to generate torque, the present invention can perform engine control only when the SoC of the high voltage battery 60 is sufficiently high in terms of battery management. .

In addition, since the low voltage battery 70 is charged through the high voltage battery 60 when the power generation is not performed by the BSG 20, the engine control is performed only when the SoC of the low voltage battery 70 is sufficiently high in terms of battery management. Can be done.

In this case, the determination unit 110 may determine whether each SoC is greater than or equal to the second threshold Th2 from the high voltage battery 60 and the low voltage battery 70. That is, the engine control using the BSG 20 may be performed only when the SoCs of the high voltage battery 60 and the low voltage battery 70 are both greater than or equal to the second threshold Th2.

In addition, the determination unit 110 may determine whether the BSG 20 can operate normally through the fourth condition.

At this time, the determination unit 110 may instruct the torque calculation unit 120 to perform calculation and generation of the BSG torque when all of the first to fourth conditions are satisfied.

In addition, the determination unit 110 may terminate the torque assistance of the engine 10 by the BSG 20 when one of the first to fourth conditions is not satisfied.

When the torque calculating unit 120 determines that the determination unit 110 assists the torque of the engine 10 using the BSG 20, the torque calculating unit 120 may collect the required rotation speed, the current rotation speed, and the pulley ratio of the engine 10. have. Here, the required rotation speed may be a target idle rotation speed for the engine 10 to leave the cold state.

In this case, the torque calculating unit 120 may calculate the torque of the BSG 20 for assisting the torque of the engine 10 based on the difference between the required rotational speed of the engine 10 and the current rotational speed, and the pulley ratio. Here, the torque calculating unit 120 may calculate the torque of the BSG 20 by performing PID control according to the difference between the required rotational speed and the current rotational speed.

In addition, the torque calculator 120 may generate the BSG torque calculated through the inverter 40 and the BSG 20 to increase the rotation speed of the engine 10 to the required rotation speed.

By such a configuration, the engine control apparatus 100 can reduce fuel consumption consumed immediately after cold start, thereby improving fuel economy.

Hereinafter, an engine control method when starting a hybrid vehicle of the present invention will be described with reference to FIG. 3. 3 is a flowchart of an engine control method when starting a hybrid vehicle according to an exemplary embodiment of the present invention.

The engine control method 200 at the start of the hybrid vehicle determines whether the temperature of the engine 10 is equal to or less than the first threshold Th1 (S210 and S220), and determines whether the operating conditions of the BSG 20 are satisfied. Steps S230 to S250 and S220, calculating the BSG 20 torques S260 and S270, and generating the BSG 20 torque S280.

More specifically, as shown in FIG. 3, first, it is determined whether the start of the hybrid vehicle 1 is turned on (step S210), and when it is determined that the start is not turned on, the hybrid vehicle 1 is started. Wait until

When it is determined that the hybrid vehicle 1 is started as a result of the determination in step S210, it is determined whether the temperature of the engine 10 is equal to or less than the first threshold value Th1 (step S220). In this case, it may be determined whether the temperature of the engine 10 is less than or equal to the first threshold Th1 based on the coolant temperature of the engine 10 from the coolant temperature sensor 12. It is thereby possible to determine whether the hybrid vehicle 1 is cold.

As a result of the determination in step S220, when it is determined that the temperature of the engine 10 is equal to or less than the first threshold value Th1, that is, when the engine 10 is in a cold state, it is determined whether there is no operation history of the accelerator pedal (step S230). ). At this time, it is possible to determine whether the accelerator pedal is operated from the accelerator pedal position sensor 90. As a result, it is possible to determine whether the engine 10 is in the idle state.

If it is determined in step S230 that there is no operation history of the accelerator pedal, it is determined whether both the SoC of the high voltage battery 60 and the low voltage battery 70 are greater than or equal to the second threshold value Th2 (step S240). That is, it is possible to determine whether both the high voltage battery 60 and the low voltage battery 70 maintain a sufficient state of charge from the charge levels of the high voltage battery 60 and the low voltage battery 70.

Here, since the high voltage battery 60 provides power for the BSG 20 to generate torque, the engine control may be performed only when the SoC of the high voltage battery 60 is sufficiently high in terms of battery management. In addition, since the low voltage battery 70 is charged through the high voltage battery 60 when the power generation is not performed by the BSG 20, the engine control is performed only when the SoC of the low voltage battery 70 is sufficiently high in terms of battery management. Can be done.

As a result of the determination in step S240, when it is determined that both the SoCs of the high voltage battery 60 and the low voltage battery 70 are greater than or equal to the second threshold Th2, it is determined whether the BSG 20 is capable of normal operation (step S250). That is, the state can be determined from the BSG 20.

Here, the steps S220 to S250 are for determining the operating conditions of the BSG 20, and the order of the steps S230 to S250 may be changed. However, step S220 may be performed first because it is for determining whether the cold state after the initial startup.

When the operating conditions of the BSG 20 are not satisfied, that is, the temperature of the engine 10 is greater than or equal to the first threshold Th1 in step S220, the accelerator pedal operates in step S230, or the high voltage in step S240. When the SoC of the battery 60 or the low voltage battery 70 is less than or equal to the second threshold Th2 or if it is determined in step S240 that the BSG 20 is not normally operable, the engine control method 200 may end. .

As a result of the determination in step S250, when it is determined that the BSG 20 can operate normally, that is, when all the operating conditions of the BSG 20 are satisfied, the required rotation speed, the current rotation speed, and the pulley ratio of the engine 10 are collected. (Step S260). Here, the required rotation speed may be a target idle rotation speed for the engine 10 to leave the cold state.

Next, the BSG 20 torque for assisting the torque of the engine 10 is calculated based on the required rotation speed, the current rotation speed, and the pulley ratio of the engine 10 (step S270). At this time, the torque of the BSG 20 for assisting the torque of the engine 10 may be calculated based on the difference between the required rotational speed of the engine 10 and the current rotational speed, and the pulley ratio. Here, the BSG 20 torque may be calculated by performing PID control according to the difference between the required rotational speed and the current rotational speed.

Next, the BSG 20 torque calculated to increase the rotational speed of the engine 10 to the required rotational speed is generated (step S280). In this case, the calculated BSG 20 torque may be applied to the inverter and the BSG 20 to generate the BSG 20 torque.

Next, the process may return to step S220 to repeat steps S220 to S270 continuously while the engine 10 temperature is maintained below the first threshold Th1.

By such a method, the engine control method 200 may reduce fuel consumption immediately after cold start, thereby improving fuel economy.

Such methods may be implemented by the engine control apparatus 100 as shown in FIG. 2, and in particular, by a software program that performs these steps, in which case these programs may be computer readable recording. The data may be stored in a medium or transmitted by a computer data signal combined with a carrier in a transmission medium or a communication network.

At this time, the computer readable recording medium includes all kinds of recording devices in which data readable by a computer system is stored, for example, ROM, RAM, CD-ROM, DVD-ROM, DVD-RAM, magnetic tape , Floppy disk, hard disk, optical data storage, and the like.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiments set forth herein, and those skilled in the art who understand the spirit of the present invention, within the scope of the same idea, the addition of components Other embodiments may be easily proposed by changing, deleting, adding, and the like, but this will also fall within the spirit of the present invention.

1: vehicle 10: engine
10a: pulley 11: ignition switch
12 coolant temperature sensor 14 belt
20: BSG 20a: Pulley
30: electronic control unit 40: inverter
50: converter 60: high voltage battery
70: low voltage battery 80: electric load
90: accelerator pedal position sensor 100: engine control device
110: determination unit 120: torque calculating unit

Claims (9)

Collects state information of the ignition switch, the coolant temperature sensor, the high voltage battery, the low voltage battery, and the accelerator pedal position sensor, and determines whether the engine temperature is lower than or equal to the first threshold after the vehicle is started. A determination unit that determines whether or not an operation condition of the BSG is less than a threshold and there is no operation history of the accelerator pedal; And
When the operating conditions of the BSG are satisfied, the required rotational speed, the current rotational speed and the pulley ratio of the engine are collected, and the BSG torque for assisting the torque of the engine is calculated based on the rotational speed of the engine. Includes; Torque calculation unit for generating the calculated BSG torque to increase,
The operation unit calculates the BSG torque by performing PID control according to the difference between the requested rotational speed and the current rotational speed, and the requested rotational speed is a target idle rotational speed for the engine to leave the cold state. Municipal engine control unit. The method of claim 1,
The determination unit may include a first condition in which the temperature of the engine is less than or equal to the first threshold value, a second condition without a history of an accelerator pedal, a third condition in which all of the SoCs of the high voltage battery and the low voltage battery are greater than or equal to the second threshold value, And determining whether the BSG satisfies a fourth condition capable of normal operation. The method of claim 2,
The determination unit instructs the operation unit to perform calculation and generation of the BSG torque when all of the first to fourth conditions are satisfied;
The engine control apparatus at the start of the hybrid vehicle which terminates the torque assistance of the engine by the BSG when any one of the first to fourth conditions is not satisfied. delete A first judging step of judging whether the temperature of the engine is less than or equal to the first threshold after the vehicle is started and there is a history of operation of the accelerator pedal;
A second determination step of determining whether an operating condition of a bet driven integrated starter generator (BSG) is satisfied when the temperature of the engine is equal to or less than a first threshold value and there is no operation history of the accelerator pedal;
Calculating a BSG torque for assisting torque of the engine based on a required rotation speed, a current rotation speed, and a pulley ratio of the engine when the operation condition of the BSG is satisfied;
Generating the calculated BSG torque to increase the rotational speed of the engine;
In the calculating, the BSG torque may be calculated by performing PID control according to a difference between the required rotational speed and the current rotational speed, and the rotational speed is a hybrid idle vehicle which is a target idle rotational speed for the engine to exit the cold state. Engine control method at start-up. The method of claim 5,
And collecting the required number of revolutions of the engine, the current number of revolutions, and the pulley ratio before the calculating step. The method of claim 5,
The second determination step,
A first step of determining whether the temperature of the engine is kept below the first threshold value;
Determining whether there is no operation history of the accelerator pedal;
Determining whether both the high voltage battery and the low voltage battery SoC are greater than or equal to the second threshold value; And
And a fourth step of determining whether the BSG is capable of normal operation. The method of claim 7, wherein
Performing the calculating and generating steps when all of the first to fourth steps are satisfied in the second judging step;
The engine control method at the start of the hybrid vehicle to terminate the torque assistance of the engine by the BSG, if any one of the first step to the fourth step is not satisfied. delete

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