KR101755498B1

KR101755498B1 - Regenerative braking apparatus for vehicle and method of the same

Info

Publication number: KR101755498B1
Application number: KR1020150169090A
Authority: KR
Inventors: 최금림
Original assignee: 현대자동차 주식회사
Priority date: 2015-11-30
Filing date: 2015-11-30
Publication date: 2017-07-27
Also published as: KR20170063103A

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerative braking control device for a vehicle, and more particularly, to a regenerative braking control device and method for a vehicle that can vary a creep torque according to a running situation so that creep traveling can be performed at a low speed.
To this end, the regenerative braking control system for a vehicle according to an embodiment of the present invention includes a speed detector for detecting a vehicle speed, which is a speed of the vehicle; An accelerator pedal position detecting unit for detecting an operation of an accelerator pedal and detecting accelerator pedal position information; And a vehicle controller that decelerates the vehicle speed based on the deceleration creep torque when the vehicle speed is equal to or lower than the reference speed and performs the regenerative braking and performs the creep traveling based on the oscillation creep torque when the vehicle speed is the set speed.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerative braking control apparatus for a vehicle,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerative braking control apparatus for a vehicle, and more particularly, to a regenerative braking control apparatus and method for a vehicle capable of varying a creep torque according to a running situation so as to enable a creep running at a low speed.

The use of pollution-free energy is becoming increasingly important as the environmental pollution problem of the earth becomes serious every day. Especially, the problem of air pollution in big cities is becoming serious day by day, and automobile exhaust gas is one of the main causes.

Eco-friendly vehicles including hybrid vehicles and electric vehicles have been developed and operated in order to solve problems related to exhaust gas and provide fuel economy improvement.

An eco-friendly vehicle means that two or more different power sources are efficiently combined to drive the vehicle. That is, the eco-friendly vehicle has power generated by the engine and the motor, and is driven by appropriately using the power generated from the combustion operation of the engine and the power generated from the rotation of the motor mediated by the electric energy stored in the battery.

Eco-friendly vehicles use regenerative braking technology to improve fuel economy.

If the brake is operated and the deceleration is executed while the environmentally friendly vehicle is running, the inertia force for driving the vehicle is generated. In this case, the motor is operated in reverse by the inertia force to operate as a generator, .

The regenerative braking system uses part of the braking force for power generation at the braking of the vehicle, charges the electric energy to the battery, and uses a part of the kinetic energy due to the running speed of the vehicle as energy required for driving the generator. Thus, the regenerative braking system refers to a system that simultaneously realizes reduction of kinetic energy and generation of electric energy.

Regenerative braking force varies with the APS (Accelerator Position Sensor) for eco-friendly vehicles without the regenerative braking system. However, since such a vehicle has a regenerative braking force even at low speed, it is incapable of driving the creep, so that it is inconvenient in low speed traveling such as oscillation and parking.

The matters described in the background section are intended to enhance the understanding of the background of the invention and may include matters not previously known to those skilled in the art.

An embodiment of the present invention provides a regenerative braking control apparatus and method for a vehicle capable of varying creep torque according to a running situation so that creep traveling can be performed even at a low speed.

Further, an embodiment of the present invention provides a regenerative braking control apparatus and method for a vehicle that decelerates based on a deceleration creep torque when the vehicle decelerates and controls the running based on the oscillation creep torque when the vehicle stops.

According to an embodiment of the present invention, there is provided a vehicle speed detecting apparatus for detecting a vehicle speed that is a speed of a vehicle. An accelerator pedal position detecting unit for detecting an operation of an accelerator pedal and detecting accelerator pedal position information; And a vehicle controller that decelerates a vehicle speed based on a deceleration creep torque when the vehicle speed is equal to or lower than a reference speed and performs a regenerative braking and performs a creep traveling based on an oscillation creep torque when the vehicle speed is a set speed, The regenerative braking control device of Fig.

If the vehicle speed is not the set speed, the vehicle controller determines whether the accelerator pedal position information is equal to or greater than the set value. If the accelerator pedal position information is equal to or greater than the set value, the vehicle controller determines whether the driver's requested torque is equal to or less than the first reference torque. When the driver's requested torque is equal to or lower than the first reference torque, the vehicle speed can be decelerated based on the deceleration creep torque.

Also, the first reference torque may be set based on the deceleration creep torque.

Further, the vehicle controller may determine whether the driver's requested torque exceeds a second reference torque when the driver's requested torque exceeds a first reference torque, and if the driver's requested torque exceeds a second reference torque, A creep running can be performed.

Also, the second reference torque may be set based on the oscillation creep torque.

Further, the vehicle controller can control the running of the vehicle based on the set creep torque when the driver's required torque exceeds the first reference torque and is equal to or less than the second reference torque.

Further, the set cryptotone may be set based on the deceleration creep torque and the oscillation creep torque.

In another embodiment of the present invention, it is determined whether the vehicle speed is lower than a reference speed. Decelerating the speed of the vehicle based on deceleration creep torque and performing regenerative braking if the vehicle speed is below a reference speed; Determining whether the vehicle speed is zero by the deceleration creep torque; And if the vehicle speed is zero, creeping the vehicle based on the oscillation creep torque.

The embodiment of the present invention can change the creep torque depending on the running situation so that the creep traveling can be performed even at a low speed, so that the regenerative braking can be performed even if the regenerative braking system is not in the vehicle.

In addition, when the vehicle decelerates, deceleration is performed on the basis of the deceleration creep torque, and when the vehicle is stopped, the running can be controlled based on the oscillation creep torque, thereby improving the driver's convenience.

In addition, effects obtainable or predicted by the embodiments of the present invention will be directly or implicitly disclosed in the detailed description of the embodiments of the present invention. That is, various effects to be predicted according to the embodiment of the present invention will be disclosed in the detailed description to be described later.

1 is a view schematically showing a hybrid vehicle including a regenerative braking control device according to an embodiment of the present invention.
2 is a view showing a regenerative braking control apparatus for a vehicle according to an embodiment of the present invention.
3 is a flowchart showing a regenerative braking control method of a vehicle according to an embodiment of the present invention.
4 is an exemplary diagram for explaining a regenerative braking control method for a vehicle according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an operation principle of an embodiment of a regenerative braking control apparatus and method for a vehicle according to the present invention will be described in detail with reference to the accompanying drawings and description. It should be understood, however, that the drawings and the following detailed description are exemplary and explanatory of various embodiments for effectively illustrating the features of the present invention. Therefore, the present invention should not be limited to the following drawings and descriptions.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The terms used below are defined in consideration of the functions of the present invention, which may vary depending on the user, intention or custom of the operator. Therefore, the definition should be based on the contents throughout the present invention.

In order to efficiently explain the essential technical features of the present invention, the following embodiments will appropriately modify, integrate, or separate terms to be understood by those skilled in the art to which the present invention belongs , And the present invention is by no means thereby limited.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view schematically showing a hybrid vehicle including a regenerative braking control device according to an embodiment of the present invention.

The hybrid vehicle of FIG. 1 is shown as an embodiment for convenience of explanation. Therefore, the regenerative braking control method of the vehicle according to the embodiment of the present invention can be applied not only to the hybrid vehicle of FIG. 1 but also to all other hybrid vehicles.

1, a hybrid vehicle includes an engine 110, an engine clutch 120, a drive motor 130, a battery 140, a transmission 150, and an engine control unit (hereinafter referred to as an ECU) And a Traction Control System (hereinafter referred to as 'TCS') 160, a motor control unit (MCU) 170, a transmission control unit (TCU) , And a hybrid control unit (HCU) (hereinafter, referred to as HCU).

The thrust is controlled by the engine 160 under the control of the ECU 160, and the driving of the engine 110 is controlled to the optimum operating point under the control of the ECU 160. [

The engine clutch 120 is disposed between the engine 110 and the drive motor 130 and is operated under the control of the HCU 200 to intercept power transmission between the engine 110 and the drive motor 130. That is, the engine clutch 120 connects or disconnects the power between the engine 110 and the drive motor 130 in accordance with the switching between the EV (Electric Vehicle) mode and the HEV (Hybrid Electric Vehicle) mode.

When the engine clutch 120 is open, the hybrid vehicle is driven only by the drive motor 130, so that the hybrid vehicle is driven by the drive motor 130. When the engine clutch 120 is locked, Or may be driven by the engine 110 and the drive motor 130 only.

The driving motor 130 is operated by the three-phase AC voltage applied from the MCU 170 to generate torque. The drive motor 130 is operated as a generator during the other running or regenerative braking to supply a voltage to the battery 140.

The battery 140 is composed of a plurality of unit cells, and a high voltage for providing a driving voltage to the driving motor 130 is stored. The battery 140 supplies the drive voltage to the drive motor 130 in the EV mode or the HEV mode and is charged with the voltage generated by the motor during the regenerative braking.

The battery 140 may be charged by the voltage and current supplied through the charging device when the commercial power source is plugged in.

The transmission 150 adjusts the transmission ratio under the control of the TCU 180 and distributes the applied output torque through the engine clutch 120 to the drive wheels according to the operation mode to deliver the output torque to the drive wheels to drive the hybrid vehicle .

The ECU 160 is connected to the HCU 200 via a network and is interlocked with the HCU 200 to control the engine operation state such as the driver's required torque signal, cooling water temperature, engine speed, throttle valve opening, And controls the overall operation of the engine 110 according to the operation of the engine 110. The ECU 160 provides the operating state of the engine 110 to the HCU 200.

The MCU 170 controls driving and torque of the driving motor 130 under the control of the HCU 200 and stores the voltage generated by the driving motor 130 in the battery 140 during the regenerative braking.

The TCU 180 controls the overall operation of the transmission 150 by controlling the speed ratio according to the output torque of the ECU 160 and the MCU 170 and determining the regenerative braking amount. The TCU 180 provides the operating state of the transmission 150 to the HCU 200.

The TCS 190 is a safety system that controls the driving force of the hybrid vehicle so that excessive driving force is generated at the time of starting or accelerating on an eye, an ice sheet, or an asymmetric road surface so that the tire does not slip.

The TCU 180 and the TCS 190 cooperate with each other to control the output torque of the engine 110 by adjusting the fuel injection amount, the ignition timing, the throttle valve and the like. The output torque of the drive motor 130 Can be controlled simultaneously.

The HCU 200 is a top-level controller for setting the hybrid traveling mode and controlling the overall operation of the hybrid vehicle. The HCU 200 controls the output torque of the engine 110 and the driving motor 130 by integrally controlling the lower controllers connected through the network, collecting and analyzing information of the lower controllers, and performing cooperative control.

The conventional operation of the hybrid vehicle according to the present invention including the above-described functions is the same as or similar to that of the conventional hybrid vehicle, so a detailed description thereof will be omitted.

2 is a view showing a regenerative braking control apparatus for a vehicle according to an embodiment of the present invention. Some of the processors of the vehicle regenerative braking control method according to an embodiment of the present invention may be performed by the ECU 160 and some of the other processors may be performed by the MCU 170 or the HCU 200. [ Therefore, the ECU 160, the MCU 170, and the HCU 200 according to the embodiment of the present invention can be described as one vehicle controller. For convenience of description, in the present specification and claims, The ECU 160, the MCU 170, and the HCU 200 will be referred to as a vehicle controller.

2, the regenerative braking control system of the vehicle includes a speed detector 210, an accelerator position sensor 220 (hereinafter, referred to as APS), a brake pedal position sensor BPS ', 230), and a vehicle controller 250. [

The speed detector 210 detects the speed of the vehicle and provides the detected vehicle speed to the vehicle controller 250.

The APS 220 measures the extent to which the driver depresses the accelerator pedal. That is, the APS 220 continuously measures the position value of the accelerator pedal (degree of depression of the accelerator pedal) and provides the monitored accelerator pedal position information to the vehicle controller 250. When the accelerator pedal is fully depressed, the position value of the accelerator pedal is 100%, and when the accelerator pedal is not depressed, the position value of the accelerator pedal is 0%.

Instead of using the APS 220, a throttle valve opening degree detection unit mounted in the intake passage can be used. Accordingly, in the present specification and claims, the APS 220 should be considered to include a throttle valve opening degree detecting section.

The BPS 230 measures the extent to which the driver depresses the brake pedal. That is, the BPS 230 provides the vehicle controller 250 with brake pedal position information that measures the position value of the brake pedal. When the position of the brake pedal is 100% when the BPS 230 is fully depressed, and when the brake pedal is not depressed, the position value of the brake pedal may be 0%.

The vehicle controller 250 decelerates the vehicle speed based on the deceleration creep torque if the vehicle speed is lower than the reference speed during deceleration. Here, the cryptot represents the torque required when the vehicle is traveling in a creep (meaning that the vehicle is driven without depressing the accelerator pedal and brake pedal), and the deceleration cryptotone is required to gradually decelerate the vehicle without depressing the brake pedal As shown in Fig. The reference speed can represent the speed at which the deceleration creep torque meets the oscillation creep torque. The vehicle controller 250 controls the motor to decelerate the speed of the vehicle using deceleration creep torque to perform regenerative braking.

The vehicle controller 250 controls the creep traveling based on the oscillation creep torque when the vehicle speed is the set speed. Here, the oscillating cryogenic torque can represent a torque required for gradually increasing the speed of the vehicle without depressing the accelerator pedal.

A method for controlling the regenerative braking will be described in more detail with reference to FIGS. 3 and 4. FIG.

For this purpose, the vehicle controller 250 may be embodied as one or more processors operating according to a set program, and the set program may be programmed to perform each step of the vehicle regenerative braking control apparatus according to an embodiment of the present invention Lt; / RTI >

Hereinafter, a method of controlling the regenerative braking of the vehicle will be described with reference to FIGS. 3 and 4. FIG.

FIG. 3 is a flowchart illustrating a method for controlling a regenerative braking of a vehicle according to an embodiment of the present invention. FIG. 4 is a diagram for explaining a regenerative braking control method for a vehicle according to an embodiment of the present invention.

Referring to FIG. 3, the vehicle controller 250 determines whether the vehicle speed is less than the reference speed (S310). That is, the vehicle controller 250 determines whether the vehicle is decelerating based on the vehicle speed, the accelerator pedal position information, and the brake pedal position information, and determines whether the vehicle speed is less than the reference speed during deceleration. Here, the reference speed may represent the speed at which the deceleration creep torque 410 and the oscillation creep torque 420 meet as shown in FIG.

On the other hand, the vehicle controller 250 monitors whether the vehicle speed becomes less than the reference speed when the vehicle speed is equal to or higher than the reference speed.

If the vehicle speed is less than the reference speed, the vehicle controller 250 decelerates the vehicle speed using the deceleration creep torque (S315). At this time, the deceleration cryptokes can perform regenerative braking because the braking force is maintained until the vehicle stops. That is, the vehicle controller 250 controls the motor while reducing the speed of the vehicle to charge the battery with voltage.

The vehicle controller 250 determines whether the vehicle speed is the set speed (S320). That is, the vehicle controller 250 determines whether the vehicle speed becomes zero, which is the set speed, by the deceleration creep torque.

When the vehicle speed becomes zero, the vehicle controller 250 performs the creep running using the oscillation creep torque (S325). On the other hand, even if the brake pedal position information is 0%, the vehicle speed can be made zero by deceleration creep torque. At this time, when the oscillation cryptocross is changed, the driver decelerates, stops, and oscillates sequentially even though the driver does not operate the pedal. Therefore, the driver may think that the vehicle has stopped, but the result of the vehicle oscillation may be displayed. Accordingly, when the vehicle speed is zero, the vehicle controller 250 changes the oscillation cryptocross when the brake pedal position information is 0 or more, and oscillates the vehicle by the oscillation creep torque when the brake pedal position information becomes zero. If the vehicle pedal position information is 0 when the vehicle speed is zero, the vehicle controller 250 can perform the creep travel using the oscillation creep torque when the accelerator pedal position information becomes zero or more.

On the other hand, if the vehicle speed is equal to or higher than the reference speed, the vehicle controller 250 determines whether the accelerator pedal position information is equal to or greater than a set value (S330). At this time, the set value is a value set to determine whether the driver depresses the accelerator pedal, and may be zero.

If the accelerator pedal position information is a set value, the vehicle controller 250 returns to step S315 and uses the deceleration creep torque to decelerate the vehicle.

The vehicle controller 250 checks the driver's requested torque if the accelerator pedal position information is equal to or greater than the set value (S335). That is, the vehicle controller 250 can confirm that the driver has pressed the accelerator pedal if the accelerator pedal position information is equal to or greater than the set value. The vehicle controller 250 confirms the driver's requested torque based on at least one of the accelerator pedal position information, the brake pedal position information, and the vehicle speed.

The vehicle controller 250 determines whether the driver's requested torque is equal to or less than the first reference torque (S340). Here, the first reference torque may be set based on the deceleration creep torque. That is, as shown in FIG. 4, the first reference torque 430 may show a large amount of torque at the deceleration creep torque 410. The reason why the first reference torque is set is that the creep torque decreases when the accelerator pedal is turned on while the deceleration cryptocross running and the regenerative braking is not performed because the accelerator pedal is kept off even when the accelerator pedal is turned off.

The vehicle controller 250 decelerates the vehicle speed using the deceleration creep torque when the driver's requested torque is equal to or lower than the first reference torque (S345). 4, if the driver's requested torque is less than the first reference torque 430 as indicated by reference numeral 440, the vehicle controller 250 again uses the deceleration creep torque 410 to decelerate the vehicle speed .

The vehicle controller 250 determines whether the driver's requested torque exceeds the second reference torque when the driver's requested torque exceeds the first reference torque (S350). Here, the second reference torque can be set based on the oscillation creep torque. That is, as shown in FIG. 4, the second reference torque may exhibit a large amount of torque at the oscillation creep torque.

The reason for setting the second reference torque is as follows. If the driver's requested torque exceeds the oscillation creep torque, it is recommended to change the oscillation crypto from the deceleration creep torque when the accelerator pedal is off to secure the low-speed drive force. However, if the driver's requested torque is equal to the oscillation creep torque, it is assumed that the oscillation claw is changed, and when the acceleration pedal is turned off, the creep torque does not decrease. Accordingly, the driver does not feel a change in torque between the on and off states of the accelerator pedal, so that the second reference torque is set to be larger than the oscillation creep torque so that the accelerator pedal is turned off when the accelerator pedal is turned off. When the accelerator pedal is turned off, The torque can be reduced.

When the driver's requested torque exceeds the second reference torque, the vehicle controller 250 performs the creep driving using the oscillation creep torque (S355). 4, when the driver's requested torque exceeds the second reference torque 450 as indicated by reference numeral 460, the vehicle controller 250 controls the speed of the vehicle using the oscillation creep torque 420 do.

The vehicle controller 250 controls the running of the vehicle using the set creep torque when the driver's requested torque is equal to or lower than the second reference torque (S360). That is, the vehicle controller 250 can control the speed of the vehicle using the set creep torque when the driver's requested torque exceeds the first reference torque and is equal to or less than the second reference torque. Here, the set cryptotone may correspond to an average value of the deceleration creep torque and the oscillation creep torque. For example, the set cryptoque may be represented by reference numeral 470 as shown in FIG.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood that the invention may be varied and varied without departing from the scope of the invention.

100: Regenerative braking control device of the vehicle
110: engine
130: drive motor
140: Battery
150: Transmission
160: ECU
170: MCU
180: TCU
190: TCS
200: HCU

Claims

A speed detector for detecting a vehicle speed that is a speed of the vehicle;
An accelerator pedal position detecting unit for detecting an operation of an accelerator pedal and detecting accelerator pedal position information; And
A vehicle controller that decelerates a vehicle speed based on a deceleration creep torque when the vehicle speed is equal to or lower than a reference speed and performs a regenerative braking and performs a creep traveling based on an oscillation creep torque when the vehicle speed is a set speed;
, &Lt; / RTI &
The vehicle controller
Determining whether the driver's requested torque is equal to or less than a first reference torque when the accelerator pedal position information is equal to or greater than a preset value, And decelerates the vehicle speed based on the deceleration creep torque when the reference torque is equal to or lower than the reference torque.

delete

The method according to claim 1,
Wherein the first reference torque is set based on the deceleration creep torque.

The method according to claim 1,
The vehicle controller
Wherein when the driver's requested torque exceeds a first reference torque, it is determined whether the driver's requested torque exceeds a second reference torque, and when the driver's requested torque exceeds a second reference torque, Regenerative braking control device.

5. The method of claim 4,
And the second reference torque is set based on the oscillation creep torque.

5. The method of claim 4,
The vehicle controller
Wherein the running control of the vehicle is controlled based on the set creep torque when the driver's requested torque exceeds the first reference torque and is equal to or less than the second reference torque.

The method according to claim 6,
And the set cryogenic torque is set based on the deceleration creep torque and the oscillation creep torque.

Determining whether the vehicle speed is equal to or lower than a reference speed;
Decelerating the speed of the vehicle based on deceleration creep torque and performing regenerative braking if the vehicle speed is below a reference speed;
Determining whether the vehicle speed is zero by the deceleration creep torque;
Driving the creep based on the oscillation creep torque when the vehicle speed is zero;
Determining whether the accelerator pedal position information is equal to or greater than a predetermined value if the vehicle speed is not 0;
Confirming a driver's requested torque if the accelerator pedal position information is equal to or greater than a set value;
Determining whether the driver's requested torque is equal to or less than a first reference torque; And
If the driver's requested torque is equal to or lower than a first reference torque, decelerating the speed of the vehicle based on the deceleration creep torque and performing regenerative braking;
Wherein the regenerative braking control method comprises:

delete

9. The method of claim 8,
After the step of determining whether the driver's requested torque is equal to or less than the first reference torque,
Determining whether the driver's requested torque exceeds a second reference torque when the driver's requested torque exceeds a first reference torque; And
When the driver's requested torque exceeds a second reference torque, creeping based on the oscillation creep torque;
Further comprising the steps of:

11. The method of claim 10,
After the step of determining whether the driver's requested torque exceeds the second reference torque,
Controlling the running of the vehicle based on the set creep torque when the driver's requested torque is equal to or less than a second reference torque;
Further comprising the steps of:

12. The method of claim 11,
Wherein the set cryotome corresponds to an average value of the deceleration creep torque and the oscillation creep torque.