KR101713754B1 - Regenerative braking apparatus for vehicle and method of the same - Google Patents

Abstract

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 calculating a regenerative braking execution amount based on an output torque of a transmission in a hybrid vehicle.
To this end, an apparatus for regenerative braking of a vehicle according to an embodiment of the present invention includes an engine as a power source and a drive motor; An engine clutch disposed between the engine and the drive motor, the engine clutch selectively connecting the engine and the drive motor; A transmission that receives driving force from at least one of the engine and the driving motor by releasing or joining the engine clutch; A state detector for detecting driving state information of the vehicle; And determining whether a shift change occurs before the stop based on the operation state information, and if a shift before the stop is generated, checking a hand over ratio according to the gear position of the transmission, And a vehicle controller that sets a regenerative braking torque, confirms a regenerative braking execution amount in accordance with the regenerative braking torque, and controls regenerative braking based on the regenerative braking execution amount and the hydraulic braking amount.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] 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 calculating a regenerative braking execution amount based on an output torque of a transmission in a hybrid vehicle.

The demand for environmentally friendly vehicles has been increasing due to the demand for constant fuel efficiency improvement for vehicles and the strengthening of exhaust gas regulations of each country. Hybrid electric vehicle (HEV) is being offered as a real alternative thereto.

Hybrid vehicles can be distinguished from fuel cell vehicles and electric vehicles in a narrow sense, but in the present specification, the meaning of a hybrid vehicle includes a pure electric vehicle (EV) and a fuel cell electric vehicle (FCEV) will be.

A hybrid vehicle is a vehicle using two or more power sources and can be combined in various ways. At this time, a gasoline engine using a conventional fossil fuel or a diesel engine using a conventional fossil fuel and a motor driven by electric energy are used as a power source. The hybrid vehicle can be provided with the optimum output torque according to how the engine and the motor are operated in harmony according to the driving situation.

The hybrid vehicle may be a TMED (Transmission Mounted Electric Device) or an FMED (Frywheel Mounted Electric Device) system equipped with AT (Automatic Transmission) or DCT (Dual Clutch Transmission).

In hybrid vehicles, regenerative braking technology is used to improve fuel economy. Regenerative braking technology uses part of the braking force for power generation at the time of 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. Eco-friendly vehicles using this regenerative braking technology can improve the mileage by extending the distance traveled by the vehicle and reduce the emission of noxious gas.

However, in the hybrid vehicle equipped with an AT, since the output shaft torque transmitted during the shift can not be accurately calculated, the fuel efficiency gain obtained by the regenerative braking is lost, and the drivability is deteriorated.

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 calculating a regenerative braking execution amount based on an output torque of a transmission in a hybrid vehicle.

An embodiment of the present invention provides a regenerative braking control apparatus and method for a vehicle capable of calculating a regenerative braking execution amount based on a handover ratio of a transmission.

In an embodiment of the present invention, an engine and a drive motor, which are power sources, An engine clutch disposed between the engine and the drive motor, the engine clutch selectively connecting the engine and the drive motor; A transmission that receives driving force from at least one of the engine and the driving motor by releasing or joining the engine clutch; A state detector for detecting driving state information of the vehicle; And determining whether a shift change occurs before the stop based on the operation state information, and if a shift before the stop is generated, checking a hand over ratio according to the gear position of the transmission, And a vehicle controller for setting a regenerative braking torque, checking a regenerative braking execution amount according to the regenerative braking torque, and controlling regenerative braking on the basis of the regenerative braking execution amount and the hydraulic braking amount, .

In addition, the vehicle controller can set the target motor torque for the shifted gear range when a shift occurs before stopping.

The regenerative braking control device of the vehicle further includes a transmission controller that receives the target motor torque from the vehicle controller, sets a handover ratio based on the target motor torque, and provides the handover ratio to the vehicle controller .

Further, the transmission controller may extract a torque subtraction amount matched to the regenerative braking torque set based on the handover ratio in a transmission sensitivity table including a torque subtraction amount matched to each of a plurality of regenerative braking torques, can do.

The vehicle controller may calculate a gear ratio according to the handover ratio, and may set the regenerative braking torque based on the input torque input to the transmission and the gear ratio.

Further, the vehicle controller may set the regenerative braking execution amount by subtracting the torque subtraction amount provided from the transmission controller in the regenerative braking torque.

Further, the regenerative braking control device of the vehicle receives the regenerative braking execution amount from the vehicle controller, checks the hydraulic braking amount based on the regenerative braking execution amount, and controls the brake cylinder And may further include a brake controller.

The status detector may further include a brake pedal position sensor for detecting a position of the brake pedal; A vehicle speed sensor for detecting the speed of the vehicle; And a speed change stage detecting portion for detecting a speed change stage engaged with the transmission.

Also, the transmission may be a double clutch transmission (DCT) that performs a shift through two clutches.

In another embodiment of the present invention, it is determined whether a shift occurs when the vehicle is stopped. Setting a target motor torque for a shifted gear range when a shift occurs when the vehicle is stopped; Setting a handover ratio based on the target motor torque; Setting a regenerative braking torque based on the handover ratio; Setting a regenerative braking execution amount by performing torque intervention based on the regenerative braking torque and the torque reduction amount; And performing regenerative braking on the basis of the regenerative braking execution amount.

The embodiment of the present invention can calculate the regenerative braking execution amount based on the output torque of the transmission, so that the regenerative braking can be accurately controlled.

In addition, the hybrid vehicle having the DCT can calculate the regenerative braking execution amount based on the transmission handover ratio, thereby improving the fuel consumption and the driving performance.

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 schematic view of a regenerative braking control system for a vehicle according to an embodiment of the present invention.
2 is a flowchart showing 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 a regenerative braking control apparatus and method of 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 schematic view of a regenerative braking control system for a vehicle according to an embodiment of the present invention.

Referring to FIG. 1, a regenerative braking control device (hereinafter, referred to as regenerative braking control device) 100 of a vehicle includes a state detector 50, an engine 110, an engine clutch 120, a drive motor 130, A battery 140, a transmission 150, an engine control unit (hereinafter referred to as ECU) 160, a motor control unit (MCU) 170, a transmission controller (Hereinafter, referred to as 'HCU') 200, a control unit (collectively referred to as 'TCU') 180, an electric brake system (hereinafter referred to as EBS) 190, and a hybrid control unit .

The state detector 50 detects the operation state information necessary for controlling the regenerative braking. The state detector 50 provides the HCU 200 with the detected operation state information. The state detector 50 includes a brake pedal position sensor (hereinafter, referred to as a 'BPS') 60, a vehicle speed sensor 70,

The BPS 60 measures the extent to which the driver depresses the brake pedal. That is, the BPS 60 measures the position value of the brake pedal (degree of depression of the brake pedal) and transmits a signal to the HCU 200. When the BPS 60 is fully depressed, the position value of the brake pedal is 100%, and when the brake pedal is not depressed, the position value of the brake pedal may be 0%.

The vehicle speed sensor 70 detects the speed of the vehicle.

The speed change stage detecting unit 80 detects the speed change stage currently engaged with the transmission 150. [

The engine 110 generates power by burning the fuel. That is, the engine 110 may be a known various engine 110 such as a gasoline engine or a diesel engine using existing fossil fuels. The rotational power generated in the engine 110 is transmitted to the transmission 150 side.

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.

The driving motor 130 is operated by a three-phase AC voltage applied from the battery 140 through an inverter to generate a torque. The drive torque is operated as a generator during the other running or regenerative braking to supply the regenerative energy 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. For example, the battery 140 stores a voltage of 400 V to 450 V of direct current. The battery 140 supplies the driving voltage to the driving motor 130 in the EV mode or the HEV mode and is charged with the voltage generated by the driving motor 130 and the HSG 115 during the regenerative braking.

The transmission 150 is supplied with the input torque as the sum of the output torque of the engine 110 and the output torque of the drive motor 130 that are determined according to the engagement and disengagement of the engine clutch 120, Is selected and the driving force is outputted to the driving wheels to maintain the running. The transmission 150 can perform shifting through the torque converter.

At this time, the transmission 150 may be a Dual Clutch Transmission (DCT). The dual-clutch transmission is a transmission with two clutches for the efficiency of a manual transmission and the convenience of an automatic transmission.

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, The overall operation of the engine 110 is controlled in accordance with the operation of the engine. 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 MCU 170 controls the overall operation of the motor according to the driver's demand torque signal, the driving mode of the vehicle, and the SOC (State Of Charge) state of the battery 140.

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 sets a handover ratio according to the speed change stage of the transmission 150 when a shift occurs before stopping. Here, the handover ratio can indicate the torque sharing ratio between the motor torque before the shifting and the target motor torque after the shifting. For example, in the case of shifting from the fourth stage to the third stage, the torque sharing ratio of the fourth stage and the third stage in the transmission is defined as 0 to 1, the handover ratio becomes 0 when 100% torque is applied to the fourth stage, If 100% torque is applied to the 3rd stage, the handover ratio can be 1. Therefore, accurate torque calculation is possible when the torque transmitted to the wheel during the braking operation is calculated by the handover ratio.

The EBS 190 calculates the total braking amount required from the pedal stroke and the hydraulic pressure of the master cylinder when the braking demand of the driver is detected. The EBS 190 performs braking control to control the hydraulic pressure supplied to the brake cylinders of the driving wheels based on the calculated total braking amount. That is, the EBS 190 receives the regenerative braking execution amount from the HCU 200, confirms the hydraulic braking amount based on the regenerative braking execution amount, controls the hydraulic pressure supplied to the brake cylinder of the driving wheel according to the hydraulic braking amount do. At this time, the EBS 190 can calculate the hydraulic braking amount by subtracting the regenerative braking execution amount from the total braking amount.

For example, the EBS 190 may employ an Active Hydraulic Booster (AHB) that maximizes the electric regenerative rate.

The HCU 200 is a top-level controller for setting the hybrid traveling mode and controlling the overall operation of the vehicle. The HCU 200 integrally controls the lower controllers connected through the network. For example, the HCU 200 may be connected to lower controllers via a CAN (Controller Area Network) communication network. The HCU 200 collects and analyzes information of each of the lower controllers, and executes coordination control to control the output torque of the engine 110 and the drive motor 130.

The HCU 200 controls the MCU 170 to perform regenerative braking based on the operation state information detected by the state detector 50. That is, the HCU 200 determines whether a shift occurs before stopping based on the operation state information, and checks the handover ratio provided by the TCU 180 when a shift occurs before stopping. The HCU 200 sets the regenerative braking torque based on the handover ratio and confirms the regenerative braking execution amount in accordance with the regenerative braking torque. The HCU 200 controls to perform regenerative braking based on the regenerative braking execution amount.

A method of controlling the regenerative braking will be described in more detail with reference to Fig.

For this purpose, the HCU 200 may be implemented with one or more processors operating according to a set program, and the set program is one that is programmed to perform each step of the regenerative braking control method of the vehicle according to an embodiment of the present invention .

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

Hereinafter, a method of controlling regenerative braking in a vehicle will be described with reference to FIG.

2 is a flowchart showing a regenerative braking control method for a vehicle according to an embodiment of the present invention.

Referring to FIG. 2, the regenerative braking control device 100 detects operation state information (S210). In other words, the state detector 50 of the regenerative braking control device 100 detects at least one of the position value of the brake pedal and the vehicle speed. The state detector 50 provides the HCU 200 with the detected operation state information.

Meanwhile, the EBS 190 determines the total braking amount based on the position value of the brake pedal, and distributes the braking force based on the total braking amount.

The regenerative braking control device 100 determines whether a shift before shifting occurs (S220). That is, the TCU 180 of the regenerative braking control device 100 determines whether a shift occurs before stopping the vehicle based on the operation state information detected in step S210.

On the other hand, if the shifting control has not occurred before the stoppage, the regenerative braking control device 100 returns to step S210 to detect the operating state information.

The regenerative braking control device 100 sets a target motor torque when a shift occurs before stopping (S230). That is, when the TCU 180 of the regenerative braking control device 100 determines that a shift has occurred before stopping, the HCU 200 provides the determined result. The HCU 200 confirms that the shift has occurred before stopping based on the determination result provided from the TCU 180, and receives the shifted gear position from the state detector 50. The HCU 200 sets the target motor torque for the shifted gear range. Here, the target motor torque may represent a torque for driving the drive motor to perform the shift.

The regenerative braking control device 100 sets the handover ratio based on the target motor torque (S240). Specifically, the TCU 180 of the regenerative braking control device 100 sets a handover ratio with respect to the torque sharing ratio between the motor torque corresponding to the gear stage before shifting and the target motor torque set in step S230. The TCU 180 provides the set handover ratio to the HCU 200.

The regenerative braking control device 100 sets the regenerative braking torque based on the handover ratio (S250). In other words, the HCU 200 of the regenerative braking control device 100 receives the handover ratio from the TCU 180 and sets the regenerative braking torque based on the handover ratio. At this time, the HCU 200 calculates the gear ratio according to the handover ratio, and sets the regenerative braking torque based on the input torque and the gear ratio input to the transmission 150. [

The regenerative braking control device 100 detects the torque reduction amount (S260). Specifically, the regenerative braking control device 100 sets a shift table in which torque subtraction amounts corresponding to a plurality of regenerative braking torques are matched. At this time, if the shift table is generated before the step S260 of detecting the torque reduction amount, the order is irrelevant. On the other hand, the shift table may be generated by the regenerative braking control device 100 or may be generated and input by an operator.

The TCU 180 of the regenerative braking control device 100 extracts the torque reduction amount matched with the regenerative braking torque set in step S250 in the shift table to perform the torque intervention control. At this time, the torque intervention may indicate a control to instantaneously reduce the input torque of the transmission 150 to reduce the impact generated when the clutch 150 is attached or detached in the transmission 150 during the shifting process. And the torque reduction amount may represent a torque for reducing the regenerative braking torque input to the transmission 150. [

The regenerative braking control device 100 sets a regenerative braking execution amount based on the regenerative braking torque and the torque reduction amount (S270). That is, the TCU 180 of the regenerative braking control device 100 sets the regenerative braking execution amount by subtracting the torque reduction amount extracted in step S260 from the regenerative braking torque set in step S250.

The regenerative braking control device 100 confirms the hydraulic braking amount based on the regenerative braking execution amount (S280). That is, the EBS 190 of the regenerative braking control device 100 receives the regenerative braking execution amount from the TCU 180 and confirms the hydraulic braking amount corresponding to the regenerative braking execution amount. At this time, the EBS 190 may set the hydraulic braking amount by subtracting the regenerative braking amount from the total braking amount.

The regenerative braking control device 100 performs regenerative braking based on the hydraulic braking amount (S290). That is, the EBS 190 of the regenerative braking control device 100 can control the hydraulic pressure supplied to the brake cylinder of the driving wheel according to the hydraulic braking amount.

Therefore, according to the embodiment of the present invention, it is possible to calculate the regenerative braking execution amount based on the handover ratio of the transmission 150 in the hybrid vehicle equipped with the DCT, so that the fuel consumption and the drivability can be improved.

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.

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

Claims (14)

An engine and a drive motor as power sources;
An engine clutch disposed between the engine and the drive motor, the engine clutch selectively connecting the engine and the drive motor;
A transmission that receives driving force from at least one of the engine and the driving motor by releasing or joining the engine clutch;
A state detector for detecting driving state information of the vehicle; And
Determining whether or not a shift occurs before stopping based on the operation state information, checking a handover ratio according to a speed change stage of the transmission when a shift before a stop occurs, A vehicle controller for setting a braking torque, checking a regenerative braking execution amount according to the regenerative braking torque, and controlling regenerative braking based on the regenerative braking execution amount and the hydraulic braking amount;
And a regenerative braking control device for a vehicle. The method according to claim 1,
Wherein said vehicle controller sets a target motor torque for a shifted gear position when a shift occurs before stopping. 3. The method of claim 2,
Further comprising a transmission controller that receives the target motor torque from the vehicle controller, sets a handover ratio based on the target motor torque, and provides the handover ratio to the vehicle controller. The method of claim 3,
The transmission controller
A torque reduction amount matched to the regenerative braking torque set on the basis of the handover ratio in a transmission sensitivity table including a torque subtraction amount matched to each of a plurality of regenerative braking torques, Device. 5. The method of claim 4,
The vehicle controller
And sets the regenerative braking execution amount by subtracting a torque subtraction amount provided from the transmission controller from the regenerative braking torque. The method according to claim 1,
The vehicle controller
Calculates a gear ratio according to the handover ratio, and sets the regenerative braking torque based on the input torque input to the transmission and the gear ratio. The method according to claim 1,
And a control unit for controlling the hydraulic pressure supplied to the brake cylinder of the driving wheel in accordance with the amount of hydraulic braking to control the hydraulic pressure supplied to the braking controller based on the regenerative braking execution amount from the vehicle controller, Further comprising: a regenerative braking control device for a vehicle. The method according to claim 1,
The state detector
A brake pedal position sensor for detecting the position of the brake pedal;
A vehicle speed sensor for detecting the speed of the vehicle; And
A speed change stage detecting unit for detecting a speed change stage coupled to the transmission;
And a regenerative braking control device for a vehicle. The method according to claim 1,
Wherein the transmission is a double clutch transmission (DCT) that performs a shift through two clutches. Determining whether a shift occurs when the vehicle stops;
Setting a target motor torque for a shifted gear range when a shift occurs when the vehicle is stopped;
Setting a handover ratio based on the target motor torque;
Setting a regenerative braking torque based on the handover ratio;
Setting a regenerative braking execution amount by performing torque intervention based on the regenerative braking torque and the torque reduction amount; And
Performing regenerative braking based on the regenerative braking execution amount;
Wherein the regenerative braking control method comprises: 11. The method of claim 10,
Before the step of setting the regenerative braking execution amount
Further comprising the step of setting a transmission sensitivity table in which a torque subtraction amount is matched with each of a plurality of regenerative braking torques. 12. The method of claim 11,
The step of setting the regenerative braking execution amount
Extracting a torque reduction amount matched to the regenerative braking torque in the transmission sensitivity table; And
Setting the regenerative braking execution amount by subtracting the torque subtraction amount from the regenerative braking torque;
Wherein the regenerative braking control method comprises: 11. The method of claim 10,
The step of setting the regenerative braking torque
Calculating a gear ratio according to the handover ratio; And
Setting the regenerative braking torque based on the gear ratio and the input torque input to the transmission;
Wherein the regenerative braking control method comprises: 11. The method of claim 10,
The step of performing the regenerative braking
Confirming the hydraulic braking amount based on the regenerative braking execution amount; And
Controlling the hydraulic pressure supplied to the brake cylinder of the driving wheel according to the hydraulic braking amount;
Wherein the regenerative braking control method comprises:

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