Feed Forward and Feedback Adjustment of Motor Torque During Clutch Engagement

• US 20130274969A1
• Filed: 04/13/2012
• Published: 10/17/2013
• Est. Priority Date: 04/13/2012
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Wang, Qing, Liang, Wei, Yamazaki, Mark Steven, Ortmann, Walter Joseph, McGee, Ryan Abraham
• Granted Patent: US 10,065,626 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60K 6/48 Parallel type
• 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 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 2050/001 Proportional integral [PI] controller
• CPC Class Codes: B60W 2050/0012 Feedforward or open loop systems
• CPC Class Codes: B60W 2510/0216 Clutch engagement rate
• CPC Class Codes: B60W 2520/105 Longitudinal acceleration
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A hybrid electric vehicle having a motor and an engine that are selectively connected on a driveline and controlled by a controller. The controller is configured to schedule additional motor torque to compensate for engine inertia drag based upon a clutch pressure value and a clutch slip speed value during a period of clutch engagement. The controller is also configured to maintain vehicle acceleration using a proportional integral controller to adjust the motor torque during a period of clutch engagement.

Claims

1. A hybrid vehicle comprising:

a motor;

an engine and a battery for supplying power to the motor;

a disconnect clutch;

at least one controller configured to adjust motor torque during a period of clutch engagement after an engine start to compensate for engine inertia drag based upon a clutch pressure and a clutch slip speed.

2. The hybrid vehicle of claim 1 wherein the period of clutch engagement is terminated when a disconnect clutch between the motor and the engine is fully engaged.

3. The hybrid vehicle of claim 1 wherein the period of clutch engagement is terminated when a speed of rotation of the motor and a speed of rotation of the engine are substantially equal thereby indicating that the disconnect clutch is fully engaged.

4. The hybrid vehicle of claim 1 wherein the period of clutch engagement begins when a disconnect clutch between the motor and the engine begins to drag the engine, wherein a calibrated time window is provided prior to the beginning of the clutch engagement.

5. The hybrid vehicle of claim 4 wherein a clutch pressure signal is provided to a gain scheduling processor that obtains a feed forward torque command based upon a stored value table.

6. The hybrid vehicle of claim 1 wherein the clutch slip speed value is provided to a proportional controller that is based upon a speed of rotation of the motor and a speed of rotation of the engine, and wherein the proportional controller provides a signal requesting a change in motor torque.

7. A hybrid vehicle comprising:

a motor;

an engine and a battery for supplying power to the motor;

a clutch;

at least one controller configured to control motor torque during a period of clutch engagement after an engine start to maintain vehicle acceleration.

8. The hybrid vehicle of claim 7 wherein the controller is configured to record the vehicle acceleration immediately prior to the period of clutch engagement, wherein the vehicle acceleration is provided to a proportional integral (PI) controller as a set point of the PI controller.

9. The hybrid vehicle of claim 8 wherein a filtered vehicle acceleration signal is provided to the PI controller for closed loop control.

10. The hybrid vehicle of claim 7 wherein the controller detects a change in driver demand associated with removing pressure from an accelerator pedal or by requesting application of a brake, wherein upon detecting a change in driver demand the controller discontinues maintaining vehicle acceleration.

11. The hybrid vehicle of claim 7 wherein the controller is configured to maintain vehicle acceleration only during the period of clutch engagement.

12. A method of operating a hybrid vehicle having an engine that is selectively connected to a driveline by a disconnect clutch and a secondary power source comprising:

adjusting secondary power source torque to compensate for engine inertia drag based upon a clutch pressure and a clutch slip speed during a period of clutch engagement after an engine start to maintain vehicle acceleration.

13. The method of claim 12 further comprising terminating the period of clutch engagement when the disconnect clutch between the secondary power source and the engine is fully engaged.

14. The method of claim 12 wherein the period of clutch engagement begins when the disconnect clutch between the secondary power source and the engine begins to drag the engine, wherein the method further comprises providing a calibrated time preparation window prior to the beginning of the clutch engagement, increasing torque requested from the secondary power source prior to the beginning of the clutch engagement, and decreasing the torque requested from the secondary power source after the beginning of clutch engagement.

15. The method of claim 12 further comprising monitoring the vehicle acceleration immediately prior to the period of clutch engagement, wherein the vehicle acceleration is provided to a proportional integral (PI) controller as a set point of the PI controller.

16. The hybrid vehicle of claim 12 further comprising providing a filtered vehicle acceleration signal to a PI controller for closed loop control.

17. The hybrid vehicle of claim 12 further comprising detecting a change in driver demand associated with removing pressure from an accelerator pedal or a request for application of a brake, wherein upon detecting the change in driver demand maintaining vehicle acceleration is discontinued.