Control method for clutch of hybrid electric vehicle

• US 9,840,249 B2
• Filed: 08/07/2015
• Issued: 12/12/2017
• Est. Priority Date: 10/28/2014
• Status: Expired due to Fees

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: Choi, Kum Lim
• Primary Examiner(s): BRUSHABER, FREDERICK M
• Application Number:
  US14/821,296
• Publication Number:
  US 20160114782A1
• Time in Patent Office: 858 Days
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/387 Actuated clutches, i.e. clutches engaged or disengaged by electric, hydraulic or mechanical actuating means
• CPC Class Codes: B60K 6/442 Series-parallel switching type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2050/0087 Resetting start and end points of actuator travel
• CPC Class Codes: B60W 2050/0088 Adaptive recalibration
• CPC Class Codes: B60W 2510/0241 Clutch slip, i.e. difference between input and output speeds
• CPC Class Codes: B60W 2710/022 Clutch actuator position
• CPC Class Codes: F16D 48/06 Control by electric or electronic means, e.g. of fluid pressure
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/946 Characterized by control of driveline clutch

Abstract

A control method for a clutch of a hybrid electric vehicle including a series and parallel type of hybrid transmission, may include determining whether the hybrid electric vehicle may be operating as the parallel type, determining a hydraulic pressure of the clutch according to a demand torque of a driver when the hybrid electric vehicle may be operating as the parallel type, determining a target value of torque blending which blends a front side torque of the clutch with a motor torque and performing the torque blending, increasing the target value of the torque blending until a clutch slip may be generated, stopping the torque blending when the clutch slip may be generated, and learning a hydraulic pressure of the clutch corresponding to the front side torque of the clutch at a time when the clutch slip may be generated.

Claims

1. A control method for a clutch of a hybrid electric vehicle including a series and parallel type of a hybrid transmission, comprising:

determining whether the hybrid electric vehicle is operating as the parallel type;

determining a hydraulic pressure of the clutch according to a demand torque of a driver when the hybrid electric vehicle is operating as the parallel type;

determining a target value of torque blending which blends a front side torque of the clutch with a motor torque and performing the torque blending, wherein the front side torque is a summation of an engine output torque and a generator input torque;

increasing the target value of the torque blending until a clutch slip is generated;

stopping the torque blending when the clutch slip is generated; and

learning a hydraulic pressure of the clutch corresponding to the front side torque of the clutch at a time when the clutch slip is generated,

wherein the performing the torque blending comprises;

comparing the front side torque of the clutch with an available transfer torque of the clutch;

determining a hydraulic pressure of the clutch corresponding to the front side torque of the clutch when the front side torque of the clutch is greater than the available transfer torque of the clutch, and applying the determined hydraulic pressure of the clutch; and

performing the torque blending when the determined hydraulic pressure of the clutch is applied, and

wherein the learning the hydraulic pressure of the clutch corresponding to the front side torque of the clutch when the clutch slip is generated stores the hydraulic pressure of the clutch corresponding to the front side torque of the clutch as a value of the available transfer torque of the clutch.

2. The control method of claim 1, further comprising

controlling the clutch with the learned hydraulic pressure after learning the hydraulic pressure of the clutch corresponding to the front side torque of the clutch at the time when the clutch slip is generated.

3. The control method of claim 1, wherein the performing the torque blending increases the front side torque of the clutch and the motor torque while maintaining a wheel torque.

4. The control method of claim 1, further comprising:

outputting the motor torque to satisfy the demand torque of the driver after applying the determined hydraulic pressure of the clutch.

5. The control method of claim 1, wherein the increasing the target value of torque blending until the clutch slip is generated is maintained when a torque blending value is smaller than or equal to a predetermined value.