Apparatus and method for calculating regenerative braking amount of hybrid electric vehicle

• US 9,561,726 B2
• Filed: 11/23/2014
• Issued: 02/07/2017
• Est. Priority Date: 07/31/2014
• Status: Active Grant

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group), Kia Motors Corporation (Kia Corp.)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group), Kia Motors Corporation (Kia Corp.)
• Inventors: Kim, Sang Joon, Park, Joonyoung, Kim, Sungdeok, Jo, Kyu Hwan
• Primary Examiner(s): Heinle, Courtney
• Assistant Examiner(s): SHUDY, ANGELINA M
• Application Number:
  US14/551,025
• Publication Number:
  US 20160031325A1
• Time in Patent Office: 807 Days
• Field of Search: 701/22, 701/70
• US Class Current: 1/1
• CPC Class Codes: B60K 2006/4825 Electric machine connected or connectable to gearbox input shaft
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2260/44 by parameter estimation
• CPC Class Codes: B60L 50/13 using AC generators and AC motors
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 7/18 Controlling the braking effect B60L7/12, B60L7/14, B60L7/16 take precedence
• CPC Class Codes: B60T 1/10 by utilising wheel movement for accumulating energy, e.g. driving air compressors
• CPC Class Codes: B60T 2270/604 Merging friction therewith; Adjusting their repartition
• CPC Class Codes: B60T 8/326 Hydraulic systems
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/188 hydraulic brakes
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/30 Wheel torque
• CPC Class Codes: B60W 30/18127 Regenerative braking
• CPC Class Codes: F16D 61/00 Brakes with means for making the energy absorbed available for use F16D57/00 takes precedence
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

A method for calculating a regenerative braking amount of a hybrid electric vehicle includes calculating a first possible available charging power of a motor when regenerative braking of the hybrid electric vehicle is required; calculating a second possible charging power of the motor by using the first possible charging power of the motor; converting the second possible charging power of the motor to a torque of a wheel axle; calculating an available amount of regenerative braking by reflecting a coasting torque on the torque of the wheel axle; generating a motor torque command based on the available amount of regenerative braking; and calculating a final regenerative braking amount by monitoring a real motor torque according to the motor torque command and correcting an error.

Claims

1. A method for calculating a regenerative braking amount of a hybrid electric vehicle having a motor and a multistage transmission, comprising:

calculating a first possible charging power of the motor outputted to the multistage transmission when regenerative braking of the hybrid electric vehicle is required;

calculating a second possible charging power of the motor by using the first possible charging power of the motor based on shift efficiency of the multistage transmission;

converting the second possible charging power of the motor to a torque of a wheel axle;

calculating an available amount of regenerative braking by reflecting a coasting torque on the torque of the wheel axle;

generating a motor torque command based on the available amount of regenerative braking;

calculating a final regenerative braking amount by monitoring a real motor torque according to the motor torque command and correcting an error; and

performing regenerative braking according to the final regenerative braking amount after calculating the final regenerative braking amount,

wherein when the regenerative braking is performed, a hydraulic braking is performed of a remaining braking amount calculated by subtracting the final regenerative braking amount from a total braking amount based on signals outputted from a vehicle speed sensor and a brake pedal position sensor.

2. The method of claim 1, wherein the first possible charging power of the motor is calculated by considering a charging limit power of a battery, a consuming power of a part load, and an available charging power of the motor.

3. The method of claim 1, wherein the second possible charging power of the motor is calculated by considering the shift efficiency based on a maximum torque that the motor can output within a range of the available charging power of the motor.

4. The method of claim 3, wherein the second possible charging power of the motor is passed through a low pass filter in order to consider the shift efficiency.

5. The method of claim 1, wherein the second possible charging power of the motor is converted by using a minimum vehicle speed and a wheel speed of the hybrid electric vehicle.

6. The method of claim 1, wherein the available amount of regenerative braking is limited to a maximum available amount in a 1 speed stage of the multistage transmission.

7. An apparatus for calculating a regenerative braking amount of a hybrid electric vehicle having a motor and a multistage transmission, comprising:

a vehicle speed sensor configured to detect a vehicle speed;

a brake pedal position sensor (BPS) configured to detect a position of a brake pedal;

an electric brake system (EBS) configured to calculate a total braking amount based on signals output from the vehicle speed sensor and the brake pedal position sensor and control hydraulic pressure supplied to a brake cylinder of a wheel according to a braking amount of hydraulic pressure; and

a hybrid controller (HCU) configured to calculate a first possible charging power of the motor outputted to the multistage transmission when regenerative braking of the hybrid electric vehicle is required and a second possible charging power of the motor by using the first possible charging power of the motor based on shift efficiency of the multistage transmission, and calculate a regenerative braking amount by converting the second possible charging power of the motor to a torque of a wheel axle,

wherein the hybrid controller performs regenerative braking according to the regenerative braking amount and outputs a signal to the EBS for performing a hydraulic pressure braking so as to satisfy the total braking amount.

8. The apparatus of claim 7, wherein the hybrid controller calculates the first possible charging power of the motor by considering a charging limit power of a battery, a consuming power of a part load, and an available charging power of the motor.

9. The apparatus of claim 7, wherein the hybrid controller converts the second possible charging power of the motor to the torque of the wheel axle by using a minimum vehicle speed and a wheel speed of the hybrid electric vehicle.