KR20190080329A - Hybrid vehicle and method of controlling thereof - Google Patents

Abstract

The present invention relates to a hybrid vehicle and a control method therefor and, more specifically, to a hybrid vehicle capable of improving acceleration responsiveness after the release of a speed limitation system, and a control method therefor. According to an embodiment of the present invention, the control method for a hybrid vehicle includes: a step of determining a first time, which is a predicted time when a speed limitation device is released by the actual manipulation of an acceleration pedal, if the speed limitation device is activated and driven in a first driving mode using power from an electric motor; a step of preparing a switch if the determined first time becomes no more than a second time required for the preparation of a switch to a second driving mode at least using an engine; and a step of switching to the second driving mode when the speed limitation device is released by the actual manipulation of the acceleration pedal.

Description

≪ Desc / Clms Page number 1 > HYBRID VEHICLE AND METHOD OF CONTROLLING THEREOF

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid vehicle and a control method therefor, and more particularly, to a hybrid vehicle and a control method thereof capable of improving acceleration responsiveness after release of a speed limitation system.

The demand for environmentally friendly vehicles is increasing due to the demand for constant fuel efficiency improvement for vehicles and the strengthening of exhaust gas regulations of each country. Hybrid vehicles (Hybrid Electric Vehicle / Plug-in Hybrid Electric Vehicle, HEV / PHEV) is being provided.

Such a hybrid vehicle can provide optimal output and torque according to how the engine and motor are operated in harmony in the course of traveling with two power sources composed of an engine and a motor. Particularly, in a hybrid vehicle adopting a parallel type (TMED: Transmission Mounted Electric Drive system) hybrid system in which an electric motor and an engine clutch (EC: Engine Clutch) are mounted between the engine and the transmission, Can be simultaneously transmitted to the drive shaft.

In a typical situation of a hybrid vehicle, electric energy is used during initial acceleration (i.e., EV mode). However, since electric energy alone has a limitation in meeting the driver's required power, a moment is required to eventually use the engine as the main power source (i.e., the HEV mode). In this case, in the hybrid vehicle, when the difference between the number of revolutions of the motor and the number of revolutions of the engine is within a predetermined range, the engine clutch is engaged so that the motor and the engine rotate together. Such a hybrid vehicle structure will be described with reference to Fig.

1 shows an example of a power train structure of a general hybrid vehicle.

1, a parallel type hybrid system in which an electric motor (or a drive motor 40) and an engine clutch 30 are mounted between an internal combustion engine (ICE) 10 and a transmission 50 A powertrain of a hybrid vehicle is shown.

In such a vehicle, in general, when the driver presses the accelerator (i.e., the accelerator pedal sensor is on), the motor 40 is first driven using the power of the battery when the engine clutch 30 is open, The wheels are moved via the transmission 50 and the final drive (FD) (i.e., the EV mode). When the vehicle is gradually accelerated and a gradually larger driving force is required, the auxiliary motor (or the starting power generation motor 20) can be operated to drive the engine 10. [

The engine 10 and the motor 40 are driven together by the engine clutch 30 when the rotational speeds of the engine 10 and the motor 40 become equal to each other so that the HEV mode transition ). The engine clutch 30 is opened and the engine 10 is stopped (i.e., the EV mode transition is performed in the HEV mode) if the predetermined engine off condition such as the vehicle deceleration is satisfied. At this time, the vehicle uses the driving force of the wheel to charge the battery 70 through the motor 40, which is referred to as braking energy regeneration or regenerative braking. Therefore, the starting power generation motor 12 acts as a start motor when the engine is started, and operates as a generator at the time of rotation recovery of the engine after starting or after startup. Therefore, the hybrid start generator (HSG: Hybrid Start Generator ").

Generally, the transmission 50 may be a step-variable transmission or a multi-plate clutch such as a dual clutch transmission (DCT).

On the other hand, vehicles equipped with a speed limit control system (SLC) have recently been released. This device plays a role of limiting the vehicle speed so that it is not accelerated beyond the speed specified by the driver. In general, it is possible to set the activation state (On / Off) and the limited vehicle speed through a switch attached to the steering or the like.

When the speed limiting device is activated, the vehicle running under the limited vehicle speed is not different from the case where the speed limiting device is inactivated, but when the current vehicle speed reaches the limited vehicle speed, the vehicle is not accelerated further. However, if the driver's accelerator pedal actuation amount exceeds the predetermined threshold value (for example, 80%) in the state where the current vehicle speed has reached the limit vehicle speed, the speed limiter is inactivated and the vehicle is allowed to travel beyond the limit vehicle speed do. More specifically, when the speed limiting device is deactivated or when the vehicle travels below the limited vehicle speed, the vehicle determines the driver's requested torque based on the accelerator pedal sensor value and the brake pedal sensor value, , The running mode, and the power train (i.e., the electric motor and the engine). On the other hand, when the speed limit device is activated and the vehicle speed reaches the limit speed, the vehicle uses the virtual accelerator pedal sensor (APS) value instead of the actual accelerator pedal sensor (APS) value to maintain the vehicle speed below the limit speed When the actual accelerator pedal sensor value reaches the threshold value, the actual accelerator pedal sensor value is referred to without using the virtual accelerator pedal sensor value as the speed limiter is deactivated.

However, in the above-mentioned parallel type (TMED) hybrid vehicle, when the speed limiting device is inactivated by the operation of the accelerator pedal after reaching the limited vehicle speed in the state where the speed limiting device is activated, there is a problem that the acceleration feeling does not meet the expectation of the driver. This will be described with reference to FIG.

2 is a diagram for explaining a cause of a deceleration in acceleration feeling when a speed limiter is released in a general parallel hybrid vehicle.

In FIG. 2, four graphs sharing the horizontal axis representing time are shown. In the graph, the ordinate indicates the vehicle speed (kph), the accelerator pedal sensor (APS) value (%), Respectively.

Referring to FIG. 2, when the vehicle is traveling in the EV mode at the speed limit set in the speed limiter, when the APS value gradually rises and reaches the release threshold, the speed limiter is deactivated and the actual APS . Accordingly, it is determined that the downshift and mode switching are necessary to satisfy the required torque according to the actual APS value in the vehicle. However, since the two procedures are sequentially performed, during the time required for mode switching (i.e., the time required for engine startup, the synchronization of the engine speed and the motor speed, and the time required for each engine clutch combination) It is difficult to satisfy the required torque. Therefore, the driver can not feel the expected acceleration feeling with respect to the amount of operation of the accelerator pedal.

SUMMARY OF THE INVENTION The present invention is directed to a method of providing a faster acceleration response when a speed limiting device is released in a hybrid vehicle and a vehicle for performing the same.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, unless further departing from the spirit and scope of the invention as defined by the appended claims. It will be possible.

According to an aspect of the present invention, there is provided a method of controlling a hybrid vehicle, the method comprising: when the speed limiting device is activated and is traveling in a first travel mode using mainly the power of the electric motor, Determining a first time that is a time at which the speed limiting device is expected to be released by an actual accelerator pedal operation; Performing the switching preparation when the determined first time becomes less than or equal to a second time required for preparation for switching to a second driving mode using at least an engine; And switching to the second driving mode when the speed limiting device is released by the actual accelerator pedal operation.

Further, in the hybrid vehicle according to the embodiment of the present invention, when the speed limiting device is activated and is traveling in the first running mode mainly using the power of the electric motor, the speed limiting device is released by the actual accelerator pedal operation A start determining unit that determines a first time that is a time expected to be expected; A mode switching preparation unit for performing the switching preparation when the determined first time is equal to or less than a second time required for preparation for switching to a second driving mode using at least an engine; And a final determination unit for determining whether to switch to the second driving mode when the speed limiting device is released by the actual accelerator pedal operation.

The hybrid vehicle according to at least one embodiment of the present invention configured as described above can obtain a faster acceleration response when the speed limiting device is released.

Particularly, when the release timing of the speed limiting device is predicted and the preparation for switching to the HEV mode is performed in advance, the mode switching is performed immediately when the accelerator pedal operation amount reaches the release threshold value, thereby achieving high acceleration responsiveness.

The effects obtained by the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art from the following description will be.

1 shows an example of a power train structure of a general hybrid vehicle.
2 is a diagram for explaining a cause of a deceleration in acceleration feeling when a speed limiter is released in a general parallel hybrid vehicle.
3 is a block diagram showing an example of a control system of a hybrid vehicle that can be applied to an embodiment of the present invention.
4 illustrates an example of a method for determining a rate limiting cancellation state based on an actual APS value according to an embodiment of the present invention.
5 shows an example of a controller configuration according to an embodiment of the present invention.
FIG. 6 is a flowchart showing an example of a control process when the speed limiting device is released for acceleration responsiveness according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise. In addition, parts denoted by the same reference numerals throughout the specification denote the same components.

Before describing a control method of a hybrid vehicle according to an embodiment of the present invention, the relationship among power train controllers that can be applied to the present embodiment will be described first with reference to FIG. The configuration of Fig. 3 can be applied to the hybrid vehicle having the power train configuration of Fig. 1 described above.

3 is a block diagram showing an example of a control system of a hybrid vehicle that can be applied to an embodiment of the present invention.

3, an internal combustion engine 110 is controlled by an engine controller 210 in a hybrid vehicle to which embodiments of the present invention can be applied, and the start-up power generation motor 120 and the electric motor 140 are connected to a motor controller (MCU) : The motor control unit 220, and the engine clutch 130 can be controlled by the clutch controller 230, respectively. Here, the engine controller 210 may be an engine management system (EMS). Also, the transmission 150 is controlled by the transmission controller 250. In some cases, a controller for the start-up power generation motor 120 and a controller for each of the electric motors 140 may be separately provided.

Each controller is connected to a hybrid controller (HCU) 240 that controls the entire mode switching process as its upper controller, and is controlled by the hybrid controller 240 to change the running mode, Information and / or information necessary for engine stop control to the engine 240, or to perform an operation according to the control signal.

More specifically, the hybrid controller 240 determines whether to perform a mode change according to the driving state of the vehicle. For example, the hybrid controller determines the time when the engine clutch 130 is released, and performs control of hydraulic pressure (in case of wet engine clutch) or control of torque capacity (in case of dry engine clutch) upon release. Also, the hybrid controller 240 can determine the state of the engine clutch (Lock-up, Slip, Open, etc.) and control the fuel injection stopping point of the engine 110. Further, the hybrid controller may control the engine rotational energy recovery by transmitting a torque command to the motor controller 220 for controlling the torque of the startup power generation motor 120 for engine stop control. In addition, the hybrid controller 240 can calculate the driver's current required torque using the APS value and the BPS value, and calculate the required torque according to the virtual APS when the speed limiting device is activated.

Of course, it is apparent to those skilled in the art that the control period connection relationship and the function / division of each controller described above are illustrative and not limited to the names. For example, the hybrid controller 240 may be implemented so that the corresponding function is provided to be replaced in any one of the other controllers except for the hybrid controller 240, and the corresponding function may be distributed in two or more of the other controllers.

Hereinafter, a control method of a hybrid vehicle according to an embodiment of the present invention will be described based on the above vehicle configuration.

According to an embodiment of the present invention, it is determined whether or not a speed limit releasing situation has arrived on the basis of an actual APS value when the vehicle is traveling in the EV mode under the condition that the speed limiting device is activated. The engine starting and the number-of-revolutions synchronization control may be performed in advance so as to enable the engine clutch engagement.

First, referring to FIG. 4, a method for determining whether or not a speed limit release situation has arrived will be described.

4 illustrates an example of a method for determining a rate limiting cancellation state based on an actual APS value according to an embodiment of the present invention.

In FIG. 4, two graphs sharing the horizontal axis indicating time are shown, and the vertical axis indicates the accelerator pedal sensor value (%) and the engine / motor rotation speed (RPM) from the top to the bottom.

Referring to FIG. 4, when the vehicle travels in the EV mode with the speed limiting device activated, the actual APS value is larger than a virtual APS value by a predetermined value or greater, and 2) based on the slope of the actual APS value, (I.e., "T1") at which the actual APS is expected to reach a threshold value (hereinafter referred to as a " speed limit release threshold value " The actual APS value at the time point may be the control start threshold value according to the present embodiment. Here, the mode switching preparation time includes a time at which the engine starts cranking and a time at which the number of revolutions of the engine after starting is synchronized with the number of revolutions of the motor.

Accordingly, when the actual APS value reaches the control start threshold value, the engine is immediately started, and the motor speed and the engine speed are synchronized, the actual APS value reaches the speed limit release threshold value at the point of time T1 The engine clutch engagement can be performed immediately so that the downshift can be performed immediately. Of course, if the actual APS value does not reach the speed limit release threshold value even if T1 elapses, the engine clutch is not engaged and the EV mode travel can be maintained.

The controller configuration for the above-described control is shown in Fig.

5 shows an example of a controller configuration according to an embodiment of the present invention.

The controller 500 shown in FIG. 5 may be a hybrid controller, a controller constituting the speed limiting device, or a separate controller in addition to the controller described above. In FIG. 5, the various input / output information is as described above, and overlapping description will be omitted.

5, the controller 500 may include a start determination unit 510, a mode change preparation unit 520, and a final determination unit 530. [

The start determination unit 510 can determine whether the actual APS value exceeds the control start threshold value in the situation that the speed limit device is activated in the vehicle and the vehicle is traveling in the EV mode. For this, the start determination unit 510 may obtain T1 through the average slope of the actual APS and compare it with T2.

When the start determination unit 510 determines that the actual APS exceeds the control start threshold value, the mode switching preparation unit 520 prepares for engine clutch engagement by performing engine start and motor-to-engine speed synchronization control.

The final determination unit 530 allows the engine clutch to be engaged immediately when the actual APS reaches the speed limit release threshold value, and if not, the engine start and the EV mode travel can be maintained.

Hereinafter, the overall control process according to the present embodiment will be described with reference to FIG.

FIG. 6 is a flowchart showing an example of a control process when the speed limiting device is released for acceleration responsiveness according to an embodiment of the present invention.

Referring to FIG. 6, it can be determined whether the vehicle is running in the EV mode with the speed limiter being activated (S610, S620).

If the difference between the actual APS value and the virtual APS value is greater than the preset value (a) when the vehicle is running in the EV mode with the speed limiter being activated, the actual APS value is determined based on the slope of the actual APS value, "T1 ", which is the time until the release threshold value is reached, can be determined (S640).

When the determined T1 is equal to or less than T2, which is the mode switching preparation time (S650), the APS value at that time is set as the first threshold value (i.e., the control start threshold value). If the actual APS value exceeds the first threshold value S660), and the mode change preparation may be performed (S670). Wherein the mode switching preparation includes engine startup and speed synchronization of the engine and the motor as described above.

If the actual APS value is equal to or greater than the second threshold value (i.e., the speed limit release threshold value) (S680), the engine speed limit is released and the engine clutch is engaged to switch the mode to the HEV mode (S690A). Alternatively, if the actual APS value is smaller than the second threshold value, the engine start may be turned off and the EV mode travel may be maintained (S690B). At this time, the determination as to whether or not the actual APS value is smaller than the second threshold value may be a time point when the time corresponding to T1 has elapsed from the T1 determination time, and the engine start-off may be performed immediately according to the determination result And may be performed when a state in which the actual APS is less than the second threshold value for a predetermined time at the elapsed time T1 continues to prevent frequent engine on / off.

On the other hand, the condition under which the mode change preparation is started in the above-described embodiment may be changed as follows. For example, it is assumed that, during EV mode travel with the speed limit device active, there is a speed limit factor (e.g., a vehicle that does not have a speed camera forward but travels slower than the limit vehicle speed of the road currently on the road). Here, the existence of the speed camera and the limited vehicle speed of the road can be obtained from the navigation system, and the forward low speed vehicle can be judged through the ADAS (Advanced Driver Assistance System).

At this time, when the lane change intention is detected in the direction of the driver's passing lane (or the lane in which the vehicle is not detected in the forward direction) (for example, when the driver turns on the turn signal in the corresponding direction) If the APS value exceeds the speed limit release threshold value, the engine clutch is locked and the speed limit is released. In addition, the HEV mode A conversion can be performed. So that rapid acceleration preparation can be carried out accordingly.

The present invention described above can be embodied as computer-readable codes on a medium on which a program is recorded. The computer readable medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of the computer readable medium include a hard disk drive (HDD), a solid state disk (SSD), a silicon disk drive (SDD), a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, .

Accordingly, the above description should not be construed in a limiting sense in all respects and should be considered illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all conversions within the scope of equivalents of the present invention are included in the scope of the present invention.

Claims (19)

A control method for a hybrid vehicle,
Determining a first time when the speed limiting device is active and is in a first travel mode using primarily the power of the electric motor, the first time being the time at which the speed limiting device is expected to be released by actual accelerator pedal operation;
Performing the switching preparation when the determined first time becomes less than or equal to a second time required for preparation for switching to a second driving mode using at least an engine; And
And switching to the second traveling mode when the speed limiting device is released by the actual accelerator pedal operation. The method according to claim 1,
Wherein the determining the first time comprises:
Determining a difference between a first value that is a current value of the actual accelerator pedal sensor and a second value that is a virtual accelerator pedal sensor value of the speed limiter; And
Wherein when the difference between the first value and the second value is equal to or greater than a predetermined value, based on the slope of the actual accelerator pedal sensor value, the actual accelerator pedal sensor value Determining a time when the value is determined to be reached as the first time. 3. The method of claim 2,
Further comprising the step of determining an accelerator pedal sensor value at a time when the first time becomes equal to or less than the second time as a fourth value,
The step of performing the switching preparation comprises:
And when the first value is greater than the fourth value. The method according to claim 1,
The step of performing the switching preparation comprises:
Starting the engine; And
And synchronizing the rotational speed of the engine with the rotational speed of the electric motor. 5. The method of claim 4,
The second time may be,
An engine cranking time, and a time for synchronizing the revolution number. The method according to claim 1,
Wherein the step of switching to the second traveling mode comprises:
And engaging an engine clutch disposed between the engine and the motor. 3. The method of claim 2,
Further comprising maintaining the first driving mode when the actual accelerator pedal sensor value is less than the third value after the lapse of the first time period. The method according to claim 1,
Wherein the first traveling mode includes an EV mode,
And the second running mode includes an HEV mode. A control method for a hybrid vehicle,
Determining a speed limiting factor when the speed limiting device is activated and the vehicle is traveling in a first travel mode using mainly the power of the electric motor;
If it is determined that there is a vehicle traveling on the forward road at a speed lower than or equal to the speed limit set in the speed limiter and the lane departure intention of the driver is sensed, preparing to switch to the second driving mode using at least the engine ; And
And when the lane departure is detected, switching to the second travel mode. A computer-readable recording medium on which a program for executing a control method of a hybrid vehicle according to any one of claims 1 to 9 is recorded. In a hybrid vehicle,
When the speed limiting device is activated and is in a first travel mode using mainly the power of the electric motor, the start determining portion determines a first time, which is a time at which the speed limiting device is expected to be released by the actual accelerator pedal operation, ;
A mode switching preparation unit for performing the switching preparation when the determined first time is equal to or less than a second time required for preparation for switching to a second driving mode using at least an engine; And
And a final determination section that, when the speed limiting device is released by the actual accelerator pedal operation, determines switching to the second travel mode. 12. The method of claim 11,
The start determining unit determines,
Determining a difference between a first value, which is a current value of the actual accelerator pedal sensor, and a second value, which is a virtual accelerator pedal sensor value of the speed limiter; and if the difference between the first value and the second value is equal to or greater than a predetermined value, And determines, based on the slope of the pedal sensor value, the first time when the actual accelerator pedal sensor value is determined to reach a third value that is an actual accelerator pedal sensor value at which the speed limiting device is released. 13. The method of claim 12,
The start determining unit determines,
Determining an accelerator pedal sensor value at a time when the first time is equal to or less than the second time as a fourth value,
Wherein the mode switching preparation unit comprises:
And performs the switching preparation when the first value is greater than the fourth value. 12. The method of claim 11,
Wherein the mode switching preparation unit comprises:
Wherein the engine is started so that the number of revolutions of the engine and the number of revolutions of the electric motor are synchronized. 15. The method of claim 14,
The second time may be,
An engine cranking time, and a time to synchronize the number of revolutions. 12. The method of claim 11,
The final determination unit may determine,
And controls to engage an engine clutch disposed between the engine and the motor when determining to switch to the second running mode. 13. The method of claim 12,
The final determination unit may determine,
When the actual acceleration pedal sensor value is less than the third value after the lapse of the first time, the first driving mode is maintained. 12. The method of claim 11,
Wherein the first traveling mode includes an EV mode,
And the second traveling mode includes an HEV mode. A control method for a hybrid vehicle,
A sensing unit for sensing a speed limiting factor when the speed limiting device is activated and traveling in a first travel mode using mainly the power of the electric motor; And
Wherein when the vehicle is traveling on the forward road at a speed lower than the speed limit set by the speed limiter and the lane departure intention of the driver is sensed as a result of the detection, And a hybrid control unit for controlling the second traveling mode to be switched to the second traveling mode when the lane departure is detected through the sensing unit.

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