DRIVE TRAIN SLIP FOR VIBRATION MITIGATION DURING SKIP FIRE OPERATION

• US 20140041626A1
• Filed: 08/09/2013
• Published: 02/13/2014
• Est. Priority Date: 08/13/2012
• Status: Active Grant

• Current Assignee: Tula Technology, Incorporated
• Original Assignee: Tula Technology, Incorporated
• Inventors: WILCUTTS, Mark A., YUAN, Xin, SWITKES, Joshua P., CARLSON, Steven E., IMPEDUGLIA, John F., PARSELS, John W.
• Granted Patent: US 9,267,454 B2
• Time in Patent Office: Days
• US Class Current: 123/350
• CPC Class Codes: B60W 10/026 of lock-up clutches
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 2030/203 related or induced by the clutch
• CPC Class Codes: B60W 2710/025 Clutch slip, i.e. difference between input and output speeds
• CPC Class Codes: B60W 30/20 Reducing vibrations in the driveline
• CPC Class Codes: F02D 11/105 characterised by the function converting demand to actuation, e.g. a map indicating relations between an accelerator pedal position and throttle valve opening or target engine torque
• CPC Class Codes: F02D 2250/18 Control of the engine output torque
• CPC Class Codes: F02D 41/00 Electrical control of supply of combustible mixture or its constituents F02D43/00 takes precedence ; control of engine starters F02N11/08, electrical control of engine ignition timing F02P5/145
• CPC Class Codes: F02D 41/0087 Selective cylinder activation, i.e. partial cylinder operation deceleration cut-off F02D41/123
• CPC Class Codes: F02D 41/022 in relation with the clutch status
• CPC Class Codes: F02D 41/18 by measuring intake air flow

Abstract

A variety of methods and devices for mitigating power train vibration during skip fire operation of an engine are described. In one aspect, the slip of a drive train component (such as a torque converter clutch) is based at least in part upon a skip fire characteristic (such as firing fraction, selected firing sequence/pattern, etc.) during skip fire operation of an engine. The modulation of the drive train component slip can also be varied as a function of one or more engine operating parameters such as engine speed and/or a parameter indicative of the output of fired cylinders (such as mass air charge).

Claims

1. A method of mitigating power train vibration during skip fire operation of an engine, the method comprising:

operating an engine in a skip fire operational mode; and

modulating slip of a drive train component based at least in part upon a skip fire characteristic.

2. A method as recited in claim 1 wherein the modulated drive train component is a torque converter clutch.

3. A method as recited in claim 1 wherein the modulated drive train component is selected from the group consisting of a differential, a dual clutch transmission and a slipping clutch transmission.

4. A method as recited in claim 1 wherein the skip fire characteristic is at least one selected from the group consisting of:

a firing fraction;

a skip fire firing pattern;

a skip fire firing sequence;

one or more selected firing decisions;

a firing history;

a frequency component of a firing fraction, firing pattern or firing sequence; and

a processed characteristic of a firing fraction, firing pattern or firing sequence.

5. A method as recited in claim 1 wherein the drive train component slip is also modulated as a function of at least one engine operational parameter selected from the group consisting of engine speed and an operational engine parameter indicative of the output of fired cylinders.

6. A method of mitigating vibration during skip fire operation of an engine in a vehicle having a power train that includes a torque converter clutch, the method comprising:

operating an engine in a skip fire operational mode; and

modulating slip of a torque converter clutch based at least in part upon at least one selected from the group consisting of (i) an operational firing fraction, (ii) an operational skip fire firing pattern, (iii) an operational skip fire firing sequence, (iv) a selected firing decision, (v) a selected set of firing decisions, (vi) a frequency component of a firing fraction, firing pattern or firing sequence, and (vii) a processed characteristic of a firing fraction, firing pattern or firing sequence.

7. A method as recited in claim 6 wherein the torque converter slip modulation also varies as a function of at least one engine operational parameter selected from the group consisting of engine speed and mass air charge.

8. A method as recited in claim 6 wherein the torque converter slip modulation also varies as a function of a parameter indicative of engine speed and a parameter indicative of mass air charge.

9. A method as recited in claim 6 wherein the torque converter slip modulation also varies as a function of at least one of:

transmission gear;

an operational state of the transmission;

a differential lockup state;

a measured vibration;

an estimated vibration;

estimated or measured acoustics; and

an estimated or measured road disturbance.

10. A powertrain controller comprising:

a firing controller configured to at least sometimes direct an engine to operate in a skip fire operational mode; and

a power train component controller arranged to control the slip of a power train component based at least in part upon a skip fire characteristic.

11. A powertrain controller as recited in claim 10 wherein the skip fire characteristic is selected from the group consisting of:

a firing fraction;

a skip fire firing pattern;

a skip fire firing sequence;

one or more selected firing decisions;

a firing history;

a frequency component of a firing fraction, firing pattern or firing sequence; and

a processed characteristic of a firing fraction, firing pattern or firing sequence.

12. A powertrain controller as recited in claim 10 wherein the power train component controller is a torque converter clutch controller.

13. A powertrain controller as recited in claim 10, wherein the firing controller and the power train component controller are embodied as separate discrete devices.

14. A powertrain controller as recited in claim 10 wherein the power train component controller is further arranged to modulate the slip of the power train component as a function of engine speed.

15. A powertrain controller as recited in claim 10 wherein the power train component controller is further arranged to modulate the slip of the power train component as a function of an operational engine parameter representative of the output of each fired cylinder.

21. A powertrain controller as recited in claim 10 wherein the power train component controller is further arranged to vary the slip of the power train component as a function of at least one of:

transmission gear;

an operational state of the transmission;

a differential lockup state;

a measured or estimated vibration;

estimated or measured acoustics; and

an estimated or measured road disturbance.

16. A vehicle powertrain comprising:

an engine;

an engine controller arranged to operate the engine in a skip fire operational mode;

a transmission; and

a torque converter clutch; and

a torque converter clutch control block arranged to modulate the slip of the torque converter clutch as a function of a skip fire characteristic during skip fire operation of the engine.

17. A vehicle as recited in claim 16 wherein the skip fire characteristic is selected from the group consisting of:

a selected firing fraction;

a selected firing pattern;

a firing sequence;

one or more firing decision;

a frequency component of a firing fraction, firing pattern or firing sequence; and

a processed characteristic of a firing fraction, firing pattern or firing sequence.

18. A vehicle as recited in claim 16 wherein the torque converter clutch control block is further arranged to modulate the slip of the torque converter clutch as a function of engine speed.

19. A vehicle as recited in claim 16 wherein the torque converter clutch control block is further arranged to modulate the slip of the torque converter clutch as a function of at least one operational engine parameter representative of the output of each fired cylinder.

20. A vehicle as recited in claim 19 wherein the at least one operational engine parameter is selected from the group consisting of:

mass air charge;

manifold pressure;

cylinder charge;

ignition timing;

fuel injection timing;

cam phase;

intake valve opening and closing timing; and

exhaust valve opening and closing timing.