Method for determining amount of regenerative braking

Patent metadata

Field	Value
Publication number	US-2016129791-A1
Application number	US-201514868654-A
Country	US
Kind code	A1
Filing date	Sep 29, 2015
Priority date	Nov 12, 2014
Publication date	May 12, 2016
Grant date	—

Abstract

A method for determining an amount of regenerative braking includes: determining a possible amount of regenerative braking at a time of braking a vehicle; distributing a first amount of regenerative braking up to the possible amount of regenerative braking as the amount of regenerative braking; distributing a second amount of regenerative braking remaining from the possible amount of regenerative braking as an amount of hydraulic braking; and performing, first, regenerative braking by issuing a motor torque instruction according to the possible amount of regenerative braking and, second, friction braking using the amount of hydraulic braking.

First claim

What is claimed is:

1 . A method for determining an amount of regenerative braking comprising:
determining a possible amount of regenerative braking at a time of braking a vehicle; distributing a first amount of regenerative braking up to the possible amount of regenerative braking as the amount of regenerative braking; distributing a second amount of regenerative braking remaining from the possible amount of regenerative braking as an amount of hydraulic braking; and performing, first, regenerative braking by issuing a motor torque instruction according to the possible amount of regenerative braking and, second, friction braking using the amount of hydraulic braking.

2 . The method of claim 1 , wherein the determining of the possible amount of regenerative braking comprises:
calculating a chargeable motor power for a battery based on one or more of: a chargeable battery power, a battery load, a motor speed, and a motor chargeable torque, provided from a battery controller; operating the regenerative braking based on a vehicle speed; and multiplying the regenerative braking by a transmission gear ratio.

3 . The method of claim 1 , wherein the possible amount of regenerative braking is determined to be zero when encountering a regenerative braking limitation.

4 . The method of claim 3 , wherein the regenerative braking limitation includes one or more of: a speed change lever being set to a sports mode, an N-step, a P-step, or an R-step, a lift-foot-up (LFU) state or a speed change occurring immediately before stopping, and a speed change pattern being changed when the vehicle is climbing.

5 . The method of claim 1 , further comprising:
when determining the possible amount of regenerative braking during a speed change, determining whether a condition of a motor of the vehicle corresponds to a steady torque mode, a steady power mode, or a mode conversion during the speed change.

6 . The method of claim 5 , wherein the possible amount of regenerative braking (Regen SteadyTorque ) during the speed change in the steady torque mode condition of the motor is determined by: i) obtaining a value α by dividing a gear ratio difference (GR Diff ) before and after the speed change by a speed change time (ΔT shift ), ii) obtaining a calculated gear ratio (GR cal-SteadyTorque ) by adding a value obtained by integrating the value α in time and a before speed change step gear ratio (GR before ), and iii) multiplying the calculated gear ratio (GR cal-SteadyTorque ) by a motor torque (T MOTOR ).

7 . The method of claim 5 , wherein the possible amount of regenerative braking (Regen SteadyPower ) during the speed change in the steady power mode condition of the motor is determined by: i) obtaining a calculated gear ratio (GR cal-SteadyTorque ) by dividing a transmission input shaft speed (ω Tmin ) by a transmission output shaft speed (ω TmOut ), and ii) multiplying the calculated gear ratio (GR cal-SteadyTorque ) by a motor torque (T MOTOR ).

8 . The method of claim 5 , wherein the possible amount of regenerative braking (Regen MotorChange ) during the speed change in the mode conversion of the motor is determined by: i) obtaining the calculated gear ratio (GR cal-ModeChange ) by integrating, at a time of the speed change, a gradient (γ) obtained by adding the increase-decrease gradient α of the gear ratio in a steady torque region of the motor and an increase-decrease gradient β of the gear ratio in a steady power region of the motor, ii) adding a virtual motor torque (T motor-virtual ) to the calculated gear ratio (GR cal-ModeChange ), and iii) adding a step gear ratio (GR before ) before the speed change to the gradient (γ).

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Huh Jee Wook
• Kim Sang Joon
• Du Gwang Il
• Cho Teh Hwan
• Choi Woo Suk
• Oh Kyoung Cheol

Classifications

• B60L7/26 Primary

  Controlling the braking effect · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• Y02T10/70

  Energy storage systems for electromobility, e.g. batteries · CPC title

• Y02T10/72

  Electric energy management in electromobility · CPC title

• B60L2240/12

  Speed · CPC title