EP-4714717-A9 - APPARATUS AND METHOD FOR CONTROLLING VEHICLE BRAKING USING BLENDING OF REGENERATIVE BRAKING AND AUXILIARY BRAKING

EP4714717A9EP 4714717 A9EP4714717 A9EP 4714717A9EP-4714717-A9

Abstract

An apparatus for controlling vehicle braking using blending of regenerative braking and auxiliary braking is provided. The apparatus includes an information input unit configured to receive vehicle travel information, a first energy determination unit configured to determine, based on the vehicle travel information, expected charging energy on a travel road, a second energy determination unit configured to determine, based on the vehicle travel information, chargeable energy available by regenerative braking, when a current travel road is a downhill road, and a vehicle control unit configured to control vehicle braking by comparing the expected charging energy with the chargeable energy, and determining a blending mode of blending an amount of operation of regenerative braking and an amount of operation of auxiliary braking as a braking mode according to a result of comparison.

Inventors

KIM, JIN YONG
NA, CHANG EUN
PARK, JIN HUI

Assignees

Hyundai Motor Company
Kia Corporation

Dates

Publication Date: 20260506
Application Date: 20250212

Claims (15)

An apparatus for controlling vehicle braking using blending of regenerative braking and auxiliary braking, the apparatus comprising: an information input unit configured to receive vehicle travel information; a first energy determination unit configured to determine, based on the vehicle travel information, expected charging energy on a travel road; a second energy determination unit configured to determine, based on the vehicle travel information, chargeable energy available by regenerative braking, when a current travel road is a downhill road; and a vehicle control unit configured to control vehicle braking by comparing the expected charging energy with the chargeable energy, and determining a blending mode of blending an amount of operation of regenerative braking and an amount of operation of auxiliary braking as a braking mode according to a result of comparison.
The apparatus of claim 1, wherein the first energy determination unit includes: a speed limit determination unit configured to determine, based on the vehicle travel information including at least one of vehicle state information or navigation information, whether there is forward congestion or a vehicle speed limit; and an expected charging energy determination unit configured to determine the expected charging energy using a battery output obtained based on an actual travelling speed or an expected travelling speed, depending on whether there is the forward congestion or the vehicle speed limit.
The apparatus of claim 2, wherein the expected charging energy determination unit includes: a battery output calculation unit configured to obtain, based on the vehicle travel information, motor output using an actual travelling speed or an expected travelling speed and traction force on a slope of the current travel road, and to obtain a battery output using motor output, auxiliary machinery output, and battery efficiency; and an expected charging energy calculation unit configured to obtain the expected charging energy using the battery output and travel time.
The apparatus of anyone of claims 1-3, wherein the second energy determination unit includes: a downhill determination unit configured to determine a current travel road as a downhill road when a value of the expected charging energy is less than or equal to zero; a state of charge (SOC) conversion unit configured to convert the expected charging energy into an SOC(%) when the current travel road is the downhill road; and a chargeable energy calculation unit configured to obtain the chargeable energy using a maximum SOC(%) and a current SOC(%) of a battery of a vehicle.
The apparatus of claim 4, wherein the chargeable energy calculation unit is configured to calculate the chargeable energy by subtracting the current SOC(%) from the maximum SOC(%) expressed by E 2 = SOCmax % − SOCcur % , wherein SOCmax is a maximum SOC(%) and SOCcur is a current SOC(%).
The apparatus of claim 3, or of claim 4 or 5 provided that in combination with claim 3, wherein the battery output calculation unit is configured to calculate the battery output using traction force, motor output, and the battery efficiency, using the expressions of: Ft ≥ Fdrag + Froll + Fgrade ; Mout = Ft * V 1 or V 2 m / s ; and Bout = Mout + Aout * BE , wherein Ft is traction force, Fdrag is air drag force, Froll is rolling resistance force, and Fgrade is gradability force received by a vehicle travelling on a road having an inclination angle θ, Mout is motor output, V is a travelling speed, V1 is an actual travelling speed and V2 is an expected travelling speed, Bout is a battery output, Aout is auxiliary machinery output, and BE is battery efficiency.
The apparatus of claim 6, wherein the expected charging energy calculation unit is configured to calculate, based on the battery output and travel time, the expected charging energy is expressed by: E 1 = Bout * Td = Ld / V V 1 or V 2 m / s , wherein E1 is expected charging energy, Bout is a battery output, Td is a travel distance, Ld is a downhill distance, V is a travelling speed, V1 is an actual travelling speed and V2 is an expected travelling speed.
The apparatus of anyone of claims 1-7, wherein the vehicle control unit includes: an energy comparison unit configured to compare the expected charging energy and the chargeable energy; a braking mode determination unit configured to determine the braking mode as a regenerative braking priority mode when a value of the expected charging energy is less than or equal to a value of the chargeable energy, and to determine the braking mode as the blending mode when the value of the expected charging energy is greater than the value of the chargeable energy, as a result of comparison performed by the energy comparison unit; and a braking control unit configured to control vehicle braking on the current travel road according to the determined braking mode.
The apparatus of claim 8, wherein the vehicle control unit further includes: an unchargeable energy calculation unit configured to obtain unchargeable energy by subtracting the chargeable energy from the expected charging energy; and a blending ratio determination unit configured to determine a ratio of the chargeable energy to the unchargeable energy as a blending ratio in the blending mode for blending regenerative braking and auxiliary braking.
The apparatus of claim 8 or 9, wherein the vehicle control unit is configured to control an operation of a cooling system for cooling an auxiliary braking device operating while braking is performed in the blending mode.
A method for controlling vehicle braking using blending of regenerative braking and auxiliary braking, the method comprising: an information reception step of receiving vehicle travel information; a first energy determination step of determining, based on the vehicle travel information, expected charging energy on a travel road; a second energy determination step of determining, based on the vehicle travel information, chargeable energy available by regenerative braking, when a current travel road is a downhill road; and a vehicle braking control step of controlling vehicle braking by comparing the expected charging energy with the chargeable energy, and determining a blending mode of blending an amount of operation of regenerative braking and an amount of operation of auxiliary braking as a braking mode according to a result of comparison.
The method of claim 11, wherein the first energy determination step includes: a speed limit determination step of determining, based on the vehicle travel information including at least one of vehicle state information or navigation information, whether there is forward congestion or a vehicle speed limit; and an expected charging energy determination step of determining the expected charging energy using a battery output obtained based on an actual travelling speed or an expected travelling speed, depending on whether there is the forward congestion or the vehicle speed limit.
The method of claim 12, wherein the expected charging energy determination step includes: a battery output calculation step of obtaining, based on the vehicle travel information, motor output using an actual travelling speed or an expected travelling speed and traction force on a slope of the current travel road, and obtaining a battery output using motor output, auxiliary machinery output, and battery efficiency; and an expected charging energy calculation step of obtaining the expected charging energy using the battery output and travel time.
The method of anyone of claims 11-13, wherein the second energy determination step includes: a downhill determination step of determining the current travel road as the downhill road when a value of the expected charging energy is less than or equal to zero; an SOC conversion step of converting the expected charging energy into an SOC(%) when the current travel road is the downhill road; and a chargeable energy calculation step of calculating the chargeable energy using a maximum SOC(%) and a current SOC(%) of a battery of a vehicle.
The method of claim 14, wherein the chargeable energy calculation step includes calculating the chargeable energy by subtracting the current SOC(%) from the maximum SOC(%) using the expression of E 2 = SOCmax % − SOCcur % , wherein SOCmax is a maximum SOC(%) and SOCcur is a current SOC(%), wherein the battery output calculation step includes calculating the battery output using traction force, motor output, and the battery efficiency, using the expressions of: Ft ≥ Fdrag + Froll + Fgrade ; Mout = Ft * V 1 or V 2 m / s ; and and Bout = Mout + Aout * BE , wherein Ft is traction force, Fdrag is air drag force, Froll is rolling resistance force, and Fgrade is gradability force received by a vehicle travelling on a road having an inclination angle θ, Mout is motor output, V is a travelling speed, V1 is an actual travelling speed and V2 is an expected travelling speed, Bout is a battery output, Aout is auxiliary machinery output, and BE is battery efficiency, wherein the expected charging energy calculation step includes calculating, based on the battery output and travel time, the expected charging energy expressed by E 1 = Bout * Td Td = Ld / V V 1 or V 2 m / s , Wherein E1 is expected charging energy, Bout is a battery output, Td is a travel distance, Ld is a downhill distance, V is a travelling speed, V1 is an actual travelling speed and V2 is an expected travelling speed.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) This application claims the benefit of priority to Korean Patent Application No. 10-2024-0129272 filed on September 24, 2024, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. TECHNICAL FIELD The present disclosure relates to an apparatus and method for controlling vehicle braking using blending of regenerative braking and auxiliary braking. BACKGROUND In general, commercial eco-friendly vehicles such as electric vehicles or hydrogen powdered vehicles may use a retarder, a regenerative braking or auxiliary braking device, to maintain speed when travelling on a downhill road. However, in order to maintain speed on a downhill road, existing vehicles may operate with a predetermined logic regardless of a downhill condition, and may operate with regenerative braking priority or retarder priority. A braking operation in an existing vehicle may have poor regenerative braking power generation output when using a retarder with priority, and may have poor auxiliary braking continuity performance when using regenerative braking with priority. SUMMARY The present disclosure provides an apparatus and method for controlling vehicle braking using blending of regenerative braking and auxiliary braking, the apparatus and method capable of performing vehicle braking by blending an amount of operation of regenerative braking and an amount of operation of auxiliary braking (e.g., a retarder) in an appropriate ratio according to a vehicle condition and a road condition when travelling on a downhill road. However, the present disclosure is not limited to those set forth herein, and other aspects set forth herein will be understood from the description herein. According to the present disclosure, there is provided an apparatus for controlling vehicle braking using blending of regenerative braking and auxiliary braking. The apparatus includes an information input unit configured to receive vehicle travel information, a first energy determination unit configured to determine, based on the vehicle travel information, expected charging energy (E1) on a travel road, a second energy determination unit configured to determine, based on the vehicle travel information, chargeable energy (E2) available by regenerative braking, when a current travel road is a downhill road, and a vehicle control unit configured to control vehicle braking by comparing the expected charging energy (E1) with the chargeable energy (E2), and determining a blending mode of blending an amount of operation of regenerative braking and an amount of operation of auxiliary braking as a braking mode according to a result of comparison. The first energy determination unit may include a speed limit determination unit configured to determine, based on the vehicle travel information including at least one of vehicle state information or navigation information, whether there is forward congestion or a vehicle speed limit, and an expected charging energy determination unit configured to determine the expected charging energy (E1) using a battery output (e.g., obtained) based on an actual travelling speed or an expected travelling speed, depending on whether there is the forward congestion or the vehicle speed limit. The expected charging energy determination unit may include a battery output calculation unit configured to obtain, based on the vehicle travel information, motor output, using an actual travelling speed or an expected travelling speed and traction force on a slope of the current travel road, and to obtain a battery output, auxiliary machinery output, and battery efficiency, and an expected charging energy calculation unit configured to obtain the expected charging energy (E1) using the (e.g., required) battery output and travel time. The second energy determination unit may include a downhill determination unit configured to determine a current travel road as a downhill road when a value of the expected charging energy is less than or equal to zero, an SOC conversion unit configured to convert the expected charging energy into an SOC(%) when the current travel road is the downhill road, and a chargeable energy calculation unit configured to obtain the chargeable energy (E2) using a maximum SOC(%) and a current SOC(%) of a battery of a vehicle. The chargeable energy calculation unit may be configured to calculate the chargeable energy (E2) by subtracting the current SOC(%) from the maximum SOC(%) using Equation 1 below. E2=SOCmax%−SOCcur% In Equation 1, SOCmax may be a maximum SOC(%) and SOCcur may be a current SOC(%). The battery output calculation unit may be configured to calculate the (e.g., required) battery output using (e.g., required) traction force, motor output, and battery efficiency, using Equations 2, 3, and 4 below. Ft≥Fdrag+Froll+Fgrade Mout=Ft*V1orV2m/s Bout=Mout+Aout*BE In an example embodiment, in Equation 4, BE may be a number or int