SYSTEM AND METHODS FOR ASSISTED DIRECT START CONTROL

• US 20100174465A1
• Filed: 01/02/2009
• Published: 07/08/2010
• Est. Priority Date: 01/02/2009
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Gibson, Alex O'Connor, Huffmaster, Roger Lyle
• Granted Patent: US 8,473,172 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• 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 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 2510/0604 Throttle position
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/0676 Engine temperature
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2552/15 Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: B60W 30/18027 Drive off, accelerating from standstill
• CPC Class Codes: B60W 30/18054 at stand still, e.g. engine in idling state hill holding B60W30/18118
• CPC Class Codes: B60W 30/192 Mitigating problems related to power-up or power-down of the driveline, e.g. start-up of a cold engine
• CPC Class Codes: F02D 41/021 Introducing corrections for particular conditions exterior to the engine conjoint control of vehicle sub-units for propelling the vehicle B60W30/18
• CPC Class Codes: F02D 41/022 in relation with the clutch status
• CPC Class Codes: F02D 41/062 for starting F02D41/061 takes precedence
• CPC Class Codes: F02N 11/0814 comprising means for controlling automatic idle-start-stop
• CPC Class Codes: F02N 2200/124 : Information about road conditions, e.g. road inclination or surface
• CPC Class Codes: F02N 2300/104 : Control of the starter motor torque

Abstract

Systems and methods for assisted direct start control are provided. An example method of controlling a system including an engine includes operating in a first mode during a first vehicle grade and during automatic re-starting from an engine stopped condition. The first mode includes starting the engine in a driving gear, and adjusting engine torque responsive to launch behavior. The method may further include operating in a second mode during a second vehicle grade and during automatic re-starting from an engine stopped condition. The second mode includes starting the engine in the driving gear, and adjusting one or more of a transmission forward clutch and wheel brakes responsive to launch behavior.

Claims

1. A method of controlling a system including an engine, the method comprising:

operating in a first mode during a first vehicle grade and during automatic re-starting from an engine stopped condition, the first mode including starting the engine in a driving gear, and adjusting engine torque responsive to launch behavior;

operating in a second mode during a second vehicle grade and during automatic re-starting from an engine stopped condition, the second mode including starting the engine in the driving gear, and adjusting one or more of a transmission forward clutch and wheel brakes responsive to launch behavior.

2. The method of claim 1, wherein the first vehicle grade is lower than the second vehicle grade.

3. The method of claim 2 further comprising selecting modes based on brake caliper wear.

4. The method of claim 3 including operating in the first mode during a second vehicle grade when brake caliper wear is greater than a predetermined wear threshold.

5. The method of claim 2 wherein starting the engine in a driving gear includes at least partially engaging the forward clutch to launch the vehicle from rest.

6. The method of claim 2 wherein adjusting engine torque includes adjusting one or more of air charge, fuel pulse width, and spark timing.

7. The method of claim 6 wherein, in the first operating mode, engine torque is decreased responsive to engine speed above a predetermined high threshold and engine torque is increased responsive to engine speed below a low predetermined threshold.

8. The method of claim 6 further comprising, in the second operating mode, decreasing forward clutch engagement responsive to engine speed above a predetermined high threshold and increasing forward clutch engagement responsive to engine speed below a predetermined low threshold.

9. The method of claim 8 further comprising increasing wheel brake pressure responsive to engine speed above a predetermined high threshold and decreasing wheel brake pressure responsive to engine speed below a predetermined low threshold in one or more of the first and second operating modes.

10. The method of claim 1 further comprising adjusting torque converter lock-up clutch engagement during the automatic engine re-starting.

11. A method for operating a vehicle with an engine, wheel brakes, and an automatic transmission having a forward clutch, the method comprising:

during automatic re-start from an engine stopped condition,

starting the engine in a driving gear of the transmission, and

adjusting engine torque, forward clutch engagement pressure of the transmission forward clutch, and wheel brake pressure responsive to launch behavior and longitudinal vehicle grade to smoothly launch the vehicle from rest.

12. The method of claim 11 wherein adjusting engine torque includes adjusting engine torque to a greater extent when longitudinal vehicle grade is below a predetermined grade threshold than when longitudinal vehicle grade is above a predetermined grade threshold.

13. The method of claim 11, wherein adjusting forward clutch engagement includes adjusting forward clutch engagement to a greater extent when longitudinal vehicle grade is above a predetermined grade threshold than when longitudinal vehicle grade is below a predetermined grade threshold.

14. The method of claim 11, wherein adjusting wheel brake pressure includes adjusting wheel brake pressure to a greater extent when longitudinal vehicle grade is above a predetermined grade threshold than when longitudinal vehicle grade is below a predetermined grade threshold.

15. A system for controlling an engine, the system comprising:

an engine comprising a plurality of cylinders;

an automatic transmission including a forward clutch configured to transmit torque from the engine to wheels;

wheel brakes; and

an electronic controller configured to vary engine torque, to vary forward clutch engagement pressure, and to vary wheel brake pressure during a vehicle launch responsive to longitudinal vehicle grade

16. The system of claim 15 wherein the electronic controller is configured to select an operating mode from a first and a second operating mode, and wherein engagement profiles of engine torque, forward clutch engagement pressure, and wheel brake pressure are responsive to the selected mode, the engagement profile of at least one of the engine torque, forward clutch engagement pressure, and wheel brake pressure differing between the first and second operating modes, and wherein the first operating mode is selected when longitudinal vehicle grade is below a predetermined grade threshold and the second operating mode is selected when longitudinal vehicle grade is above a predetermined grade threshold.

17. The system of claim 16 wherein the predetermined grade threshold is varied responsive to engine operating parameters.

18. The system of claim 17 wherein an operating mode is selected based on brake caliper wear.

19. The system of claim 16 further comprising, in the first operating mode, decreasing engine torque responsive to engine speed above a predetermined high threshold and increasing engine torque responsive to engine speed below a predetermined low threshold, and, in the second operating mode, decreasing forward clutch engagement pressure responsive to engine speed above a predetermined high threshold and increasing forward clutch engagement pressure responsive to engine speed below a predetermined low threshold.

20. The method of claim 19 further comprising increasing wheel brake pressure responsive to engine speed above a predetermined high threshold and decreasing wheel brake pressure responsive to engine speed below a predetermined low threshold, in one or more of the first and second operating modes.