KR102274014B1 - Regenerative braking apparatus for vehicle and method of the same - Google Patents

Abstract

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 capable of reducing an energy recovery rate loss due to torque intervention by minimizing shift control during regenerative braking.
To this end, the apparatus for controlling regenerative braking of a vehicle according to an embodiment of the present invention includes an engine as a power source and a driving motor, an engine clutch positioned between the engine and the driving motor, and selectively connecting the engine and the driving motor, and the engine. a transmission receiving driving force from at least one of the engine and the driving motor by releasing or joining the clutch; Perform regenerative braking based on an information detector for detecting driving information of the vehicle and driving information detected by the information detector, check the required amount of regenerative braking and the chargeable amount of the motor, and based on the required amount of regenerative braking and the chargeable amount of the motor and a vehicle controller that controls the transmission to hold the shift.

Description

Regenerative braking control device and method of vehicle {REGENERATIVE BRAKING APPARATUS FOR VEHICLE AND METHOD OF THE SAME}

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 capable of reducing an energy recovery rate loss due to torque intervention by minimizing shift control during regenerative braking.

The use of pollution-free energy is becoming more and more important these days as the problem of environmental pollution on the earth is getting more serious. In particular, the problem of air pollution in large cities is getting serious day by day, and exhaust gas from automobiles is one of the main causes.

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

Such a hybrid vehicle has power composed of an engine and a motor, and is driven by appropriately using power generated from combustion of the engine and power generated from rotation of the motor through electric energy stored in the battery, respectively.

In addition, an automatic transmission in which an optimum transmission ratio is automatically determined and shifted in consideration of power performance, fuel efficiency, drivability, etc. is generally applied to a hybrid vehicle.

Since the automatic transmission generates a shock when shift control is not precisely executed and causes a problem in durability, a function of quickly controlling the shock when shifting is performed is required.

In hybrid vehicles, regenerative braking is used to improve fuel efficiency. The regenerative braking technology uses a part of the braking force for power generation when braking the vehicle, charges the generated electric energy to the battery, and uses a part of the kinetic energy due to the vehicle's running speed as energy required to drive the generator. A hybrid vehicle using such a regenerative braking technology can improve fuel efficiency by extending the mileage of the vehicle, and can reduce harmful gas emissions.

In general, when regenerative braking is controlled, a downshift is performed according to a predetermined shift pattern. Such a shift pattern is usually determined by the speed of the vehicle, and when the vehicle speed is reduced, the shift stage is changed to a lower stage.

At this time, torque intervention control for reducing the charging torque of the motor is performed to secure shift performance. However, when shifting occurs frequently, the amount of regenerative braking during shifting is reduced by the intervention function, thereby reducing energy recovery efficiency, and thus overall fuel consumption may increase.

Matters described in this background section are prepared to enhance understanding of the background of the invention, and may include matters that are not already known to those of ordinary skill in the art to which this technology belongs.

An embodiment of the present invention provides an apparatus and method for controlling regenerative braking of a vehicle for performing shift control according to a required amount of regenerative braking.

Further, an embodiment of the present invention provides an apparatus and method for controlling regenerative braking of a vehicle that can maximize efficiency of regenerative braking by controlling a motor and a transmission based on a required amount of regenerative braking and a chargeable amount of the motor to perform shifting.

In an embodiment of the present invention, an engine and a driving motor as a power source; an engine clutch positioned between the engine and the driving motor and selectively connecting the engine and the driving motor; a transmission receiving driving force from at least one of the engine and the driving motor by releasing or joining the engine clutch; an information detector for detecting driving information of the vehicle; and performing regenerative braking based on the driving information detected by the information detector, checking the regenerative braking demand and the motor chargeable amount, and controlling the transmission based on the regenerative braking demand and the motor chargeable amount to hold the shift. ) to provide a regenerative braking control device for a vehicle including a vehicle controller.

In addition, the vehicle controller checks the shift stage coupled to the transmission, confirms the chargeable amount of the motor corresponding to the shift stage, and holds the shift when the required amount of regenerative braking is within the chargeable amount of the motor according to the shift stage can do.

Also, when the required amount of regenerative braking is greater than or equal to the chargeable amount of the motor, the vehicle controller may control the transmission to shift to a target shift stage according to the speed of the vehicle.

In addition, the chargeable amount of the motor may be set based on at least one of a motor speed torque, a rating reduction coefficient according to the motor power, and a battery chargeable power.

In addition, the battery chargeable power may be set based on the battery charge limiting power and auxiliary load consumption power which are limited according to the state of charge (SOC) and temperature of the battery.

In addition, the rating reduction coefficient according to the motor power may be set according to the state of the motor.

In addition, the information detector may include a shift stage detection unit configured to detect a shift stage coupled to the transmission; a vehicle speed sensor detecting the speed of the vehicle; and a brake pedal position sensor detecting a position of the brake pedal.

And in another embodiment of the present invention, the driving motor performs regenerative braking; checking a required amount of regenerative braking and a chargeable amount of the motor; determining whether the required amount of regenerative braking is less than the chargeable amount of the motor; and holding the shift when the required amount of regenerative braking is less than the chargeable amount of the motor.

According to the embodiment of the present invention, when the regenerative braking demand is within the range of the motor chargeable amount of the motor, unnecessary shifting is prevented, thereby preventing the regenerative torque of the motor from being reduced by the shift intervention.

In addition, the embodiment of the present invention may increase the recovery rate of regenerative energy due to the prevention of unnecessary shift during regenerative braking.

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

1 is a diagram schematically illustrating an apparatus for controlling regenerative braking of a vehicle according to an embodiment of the present invention.
2 is a flowchart illustrating a method for controlling regenerative braking of a vehicle according to an embodiment of the present invention.
3 is an exemplary diagram illustrating a motor chargeable amount for each shift stage according to an embodiment of the present invention.
4 is an exemplary view illustrating a motor chargeable amount and a required amount of regenerative braking according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings and description, the operating principle of the embodiment of the regenerative braking control apparatus and method for a vehicle according to the present invention will be described in detail. However, the drawings shown below and the detailed description given below relate to one preferred embodiment among various embodiments for effectively explaining the features of the present invention. Accordingly, the present invention should not be limited only to the following drawings and description.

In addition, in the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. And the terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of the user or operator. Therefore, the definition should be made based on the content throughout the present invention.

In addition, in the following embodiments, terms will be appropriately modified, integrated, or separated so that those of ordinary skill in the art can clearly understand the present invention in order to effectively describe the key technical features of the present invention. , the present invention is by no means limited.

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

1 is a diagram schematically illustrating an apparatus for controlling regenerative braking of a vehicle according to an embodiment of the present invention.

Referring to FIG. 1 , a vehicle regenerative braking control device (hereinafter, collectively referred to as a 'regenerative braking control device', 100) includes an information detector 50, an engine 110, and a hybrid starter & generator (hereinafter referred to as 'HSG'). 115), engine clutch 120, drive motor 130, battery 140, transmission 150, engine controller (Engine Control Unit: hereinafter collectively referred to as 'ECU', 160), motor controller ( Motor Control Unit: hereinafter collectively called 'MCU', 170), Transmission Control Unit (hereinafter collectively called 'TCU', 180), Brake Controller (Electric Brake System: hereinafter collectively called 'EBS', 190) and a hybrid vehicle controller (hereinafter referred to as 'HCU') 200 .

The information detector 50 detects driving information necessary to control the regenerative braking. The information detector 50 provides the detected driving information to the HCU 200 . The information detector 50 includes a shift stage detector 60 , a vehicle speed sensor 70 , and a brake pedal position sensor (hereinafter, collectively referred to as 'BPS', 80 ).

The shift stage detection unit 60 detects a shift stage currently fastened to the transmission 150 .

The vehicle speed sensor 70 measures the speed of the vehicle and is mounted on a driving wheel of the vehicle. The vehicle speed sensor 70 continuously detects the vehicle speed and transmits it to the HCU 200 .

Meanwhile, when the vehicle speed sensor 70 is not provided, the vehicle controller may calculate the vehicle speed based on a GPS signal received from a global positioning system (GPS).

The BPS 80 measures the degree to which the driver depresses the brake pedal. That is, the BPS 80 measures the position value of the brake pedal (the degree to which the brake pedal is pressed) and transmits a signal corresponding thereto to the HCU 200 . In the BPS 80 , when the brake pedal is fully pressed, the position value of the brake pedal may be 100%, and when the brake pedal is not pressed, the position value of the brake pedal may be 0%.

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

The HSG 115 starts the engine 110 or operates as a generator while the engine 110 is started to generate electrical energy.

The engine clutch 120 is disposed between the engine 110 and the driving motor 130 , and is operated under the control of the HCU 200 to intermittently transmit power between the engine 110 and the driving motor 130 . That is, the engine clutch 120 connects or blocks the power between the engine 110 and the driving motor 130 according to 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 torque. The driving torque is operated as a generator when traveling or regenerative braking to supply regenerative energy to the battery 140 .

The battery 140 includes 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 DC voltage of 400V to 450V. The battery 140 supplies a 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 regenerative braking.

In the transmission 150 , the sum of the output torque of the engine 110 and the output torque of the driving motor 130 , which is determined according to the engagement and disengagement of the engine clutch 120 , is supplied as an input torque, and is arbitrary depending on vehicle speed and driving conditions. is selected to maintain driving by outputting driving force to the driving wheel.

The ECU 160 is connected to the HCU 200 through a network, and is interlocked with the HCU 200 to signal the driver's required torque, coolant temperature, engine rotation speed, throttle valve opening, intake air amount, oxygen amount, and engine operating state such as engine torque. Accordingly, the overall operation of the engine 110 is controlled. The ECU 160 provides the operating state of the engine 110 to the HCU 200 .

The MCU 170 controls the 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 regenerative braking. The MCU 170 controls the overall operation of the motor according to the driver's requested torque signal, the driving mode of the vehicle, and the state of charge (SOC) state of the battery 140 .

The TCU 180 controls the overall operation of the transmission 150 , such as controlling the transmission ratio according to each output torque of the ECU 160 and the MCU 170 , and determining the amount of regenerative braking.

When the driver's braking request is detected, the EBS 190 calculates a required braking torque from the pedal stroke and hydraulic pressure of the master cylinder. In addition, the EBS 190 controls hydraulic braking supplied to the brake cylinder of each driving wheel according to the calculated braking torque.

The HCU 200 is a top-level controller that sets the hybrid driving mode and controls 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 through a controller area network (CAN) communication network. The HCU 200 collects and analyzes information of each sub-controller and executes cooperative control to control the output torque of the engine 110 and the driving motor 130 .

The HCU 200 controls the MCU 170 to perform regenerative braking based on the driving information detected by the information detector 50 . The HCU 200 checks the regenerative braking demand and the motor chargeable amount according to the driving information during regenerative braking, and controls the TCU 180 based on the regenerative braking demand and the motor chargeable amount to hold the shift or target shift stage. shift to

A method of controlling the regenerative braking will be described in more detail with reference to FIGS. 2 to 4 .

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

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

Hereinafter, a method for controlling regenerative braking of a vehicle according to an embodiment of the present invention will be described.

2 is a flowchart illustrating a method for controlling regenerative braking of a vehicle according to an embodiment of the present invention. Previously, the controllers included in the regenerative braking control apparatus 100 of a vehicle according to an embodiment of the present invention described with reference to FIG. 1 may be integrated or subdivided, regardless of the name, the above-described functions may be performed. It is clarified that the controllers to be executed may be the components of the regenerative braking control apparatus 100 of a vehicle according to an embodiment of the present invention. Therefore, in the following description of a method for controlling regenerative braking in the regenerative braking control apparatus 100 of a vehicle according to an embodiment of the present invention, the subject of each step is the regenerative braking control apparatus 100 rather than the corresponding controllers. to be explained as

The regenerative braking control apparatus 100 determines whether regenerative braking is performed (S210). That is, the regenerative braking control apparatus 100 checks whether the brake pedal is operated based on the position value of the brake pedal included in the driving information, and checks whether the driver requests regenerative braking based on the operation of the brake pedal. The regenerative braking control apparatus 100 performs regenerative braking through the driving motor 130 or the HSG 115 when the driver requests regenerative braking.

Meanwhile, the regenerative braking control device 100 monitors whether regenerative braking is being performed when regenerative braking is not being performed.

The regenerative braking control apparatus 100 sets the regenerative braking demand amount (S220). That is, the regenerative braking control apparatus 100 may set the regenerative braking demand amount based on the position value of the brake pedal. The regenerative braking demand amount may mean a total braking amount according to the position value of the brake pedal.

When the driver presses the brake pedal, the regenerative braking control device 100 performs braking with the amount of friction braking and the amount of regenerative braking, and performs regenerative braking first, and sets the total amount of braking by taking the rest with friction braking. . The required amount of regenerative braking indicates an amount by which the driving motor 130 must output charging torque in order to provide the amount of regenerative braking.

The regenerative braking control apparatus 100 sets the motor chargeable amount ( S230 ). That is, the regenerative braking control apparatus 100 may set the chargeable amount of the motor in consideration of the states of the driving motor 130 and the battery 140 , and convert the chargeable torque corresponding to each shift stage based on the wheel axis to convert the motor Rechargeable amount may be indicated. The regenerative braking control apparatus 100 may be converted in consideration of the gear ratio for each gear stage of the transmission 150 and the companion diameter of the driving wheel based on the motor speed and torque curve. For example, the motor speed torque curve may be set differently for each shift stage as shown in FIG. 3 .

The regenerative braking control apparatus 100 sets the chargeable amount of the motor for each shift stage based on a derating factor according to the motor power and the battery chargeable power. At this time, the rating reduction coefficient according to the motor power is set according to the state of the driving motor 130 . The rating reduction factor according to the motor power is a value for motor protection, and may be a value between 0 and 1. Depending on the overtemperature system of the motor, it may be set to 1 if normal, and may be set to 0 if not available, but is not limited thereto.

In addition, the battery chargeable power may be set based on the battery charge limiting power limited according to the SOC and temperature of the battery 140 and the auxiliary load consumption power consumed by the air conditioner or the heater.

The regenerative braking control apparatus 100 determines whether the regenerative braking demand amount is less than the motor chargeable amount (S240).

The regenerative braking control apparatus 100 holds the shift when the regenerative braking demand amount is less than the motor chargeable amount (S250). For example, as shown in FIG. 4 , the regenerative braking control apparatus 100 does not perform shifting when the regenerative braking demand 410 is less than the n+2-stage motor chargeable amount 410 .

The regenerative braking control apparatus 100 shifts to the target shift stage when the regenerative braking demand amount is greater than or equal to the motor chargeable amount (S260). For example, when the regenerative braking demand 420 is greater than or equal to n+2-stage motor chargeable amount 410 as shown in FIG. 4 , the regenerative braking control apparatus 100 may set the target shift stage according to the vehicle speed n+ Shift to 1st gear. By shifting to the n+1 speed, the regenerative braking demand 420 is less than the n+1 speed motor chargeable amount 425 .

As described above, since the regenerative braking control apparatus 100 according to an embodiment of the present invention does not perform shifting when the regenerative braking demand is less than or equal to the motor chargeable amount, the regenerative energy recovery rate due to unnecessary shift prevention can be increased.

Although the above has been described with reference to a preferred embodiment of the present invention, those of ordinary skill in the art can variously change the present invention within the scope without departing from the spirit and scope of the present invention described in the claims below. It will be appreciated that modifications and variations are possible.

50: information detector
100: regenerative braking control device of the vehicle
110: engine
115: HSG
120: engine clutch
130: drive motor
140: battery
150: gearbox
160: ECU
170: MCU
180: TCU
190: EBS
200: HCU

Claims (11)

engine and drive motor as power source;
an engine clutch positioned between the engine and the driving motor and selectively connecting the engine and the driving motor;
a transmission receiving driving force from at least one of the engine and the driving motor by releasing or joining the engine clutch;
an information detector for detecting driving information of the vehicle; and
Regenerative braking is performed based on the driving information detected by the information detector, and the regenerative braking demand and motor chargeable amount set as the total braking amount according to the position value of the brake pedal are checked, and based on the regenerative braking demand and the motor chargeable amount a vehicle controller that controls the transmission to hold the shift;
A regenerative braking control device for a vehicle comprising a. According to claim 1,
the vehicle controller
Regenerative braking control of a vehicle that checks a shift stage coupled to the transmission, confirms a chargeable amount of a motor corresponding to the shift stage, and holds a shift when the required amount of regenerative braking is within a chargeable amount of a motor according to the shift stage Device. According to claim 1,
the vehicle controller
A regenerative braking control apparatus for a vehicle that performs shifting to a target gear according to a speed of the vehicle by controlling the transmission when the required amount of regenerative braking is greater than or equal to the chargeable amount of the motor. According to claim 1,
The chargeable amount of the motor is set based on at least one of a motor speed torque, a rating reduction coefficient according to the motor power, and a battery chargeable power. 5. The method of claim 4,
The battery chargeable power is a regenerative braking control device for a vehicle that is set based on a battery charge limiting power limited according to a state of charge (SOC) and a temperature of the battery and auxiliary load consumption power. 5. The method of claim 4,
The regenerative braking control apparatus of a vehicle wherein the rating reduction coefficient according to the motor power is set according to the state of the motor. According to claim 1,
The information detector
a shift stage detection unit configured to detect a shift stage coupled to the transmission;
a vehicle speed sensor detecting the speed of the vehicle; and
a brake pedal position sensor for detecting the position of the brake pedal;
A regenerative braking control device for a vehicle comprising a. performing regenerative braking by the driving motor;
checking a regenerative braking demand amount and a motor chargeable amount set as a total braking amount according to a position value of a brake pedal;
determining whether the required amount of regenerative braking is less than the chargeable amount of the motor; and
holding the shift when the regenerative braking demand amount is less than the motor chargeable amount;
A method of controlling regenerative braking of a vehicle comprising a. 9. The method of claim 8,
After determining whether the required amount of regenerative braking is less than the chargeable amount of the motor,
performing a shift to a target shift stage according to the speed of the vehicle when the regenerative braking demand is greater than or equal to the chargeable amount of the motor;
Regenerative braking control method of a vehicle further comprising a. 9. The method of claim 8,
The step of checking the required amount of regenerative braking and the available amount of motor charging includes:
setting a battery chargeable power based on the battery charge limiting power and auxiliary load consumption power limited according to the SOC and temperature of the battery; and
setting a motor chargeable amount based on at least one of the battery chargeable power, the motor speed torque, and a rating reduction coefficient according to the motor power;
A method of controlling regenerative braking of a vehicle comprising a. 9. The method of claim 8,
The step of the driving motor performing regenerative braking
detecting operation of a brake pedal; and
performing regenerative braking by the driving motor through rotational force transmitted from the driving wheel when the operation of the brake pedal is sensed;
A method of controlling regenerative braking of a vehicle comprising a.

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