Systems and methods for optimization and control of internal combustion engine starting

• US 9,316,195 B2
• Filed: 10/29/2012
• Issued: 04/19/2016
• Est. Priority Date: 10/29/2012
• Status: Active Grant

• Current Assignee: Cummins Incorporated
• Original Assignee: Cummins Incorporated
• Inventors: Puri, Anant, Zeng, Fan, Sujan, Vivek, Hodzen, Edmund
• Primary Examiner(s): Huynh, Hai
• Assistant Examiner(s): NAJMUDDIN, RAZA NEHAL
• Application Number:
  US13/662,869
• Publication Number:
  US 20140116380A1
• Time in Patent Office: 1,268 Days
• Field of Search: 123/350, 123/349, 123/376, 123/179.3, 123/179.4, 701/110, 701/112, 701/113, 903/905
• US Class Current: 1/1
• CPC Class Codes: F02D 41/062 for starting F02D41/061 takes precedence
• CPC Class Codes: F02N 11/08 Circuits or control means specially adapted for starting of engines
• CPC Class Codes: F02N 11/0822 related to action of the driver
• CPC Class Codes: F02N 11/0825 related to prevention of engine restart failure, e.g. disabling automatic stop at low battery state
• CPC Class Codes: F02N 2200/022 Engine speed
• CPC Class Codes: F02N 2200/023 Engine temperature
• CPC Class Codes: F02N 2200/04 said parameters being related to the starter motor
• CPC Class Codes: F02N 2200/061 Battery state of charge [SOC]
• CPC Class Codes: F02N 2200/101 Accelerator pedal position
• CPC Class Codes: F02N 2300/102 Control of the starter motor speed; Control of the engine speed during cranking

Abstract

An engine starting system and technique include selecting a target engine speed profile from a plurality of engine speed profiles based on operator inputs and operating parameters of the vehicle. A feedback control strategy is used to substantially conform the engine speed with the target speed profile during starting until a target speed is reached in which fueling is initiated to start the engine.

Claims

1. A method, comprising:

selecting a target engine speed profile for starting an internal combustion engine of a vehicle based on operator inputs from an operator of the vehicle and operating parameters of the vehicle, wherein the operating parameters include a charge condition of at least one of a low voltage energy storage device connected to a first starter motor and a high voltage energy storage device connected to a second starter motor, and wherein selecting the target engine speed profile includes selecting one of the first starter motor and the second starter motor in response to the charge condition;

driving the internal combustion engine for a starting duration with the selected one of the first starter motor and the second starter motor in response to selecting the target engine speed profile;

determining an instantaneous engine speed during a starting duration;

regulating the speed of the internal combustion engine during the starting duration in response to the instantaneous engine speed to substantially conform the speed of the internal combustion engine with the target speed profile; and

starting the internal combustion engine when the speed of the internal combustion engine reaches a target speed of the target speed profile.

2. The method of claim 1, wherein the first starter motor is a starter and the second starter motor is a motor-generator.

3. The method of claim 1, wherein the operator inputs include an accelerator pedal position.

4. The method of claim 1, wherein the operating parameters further include at least one of an engine temperature, a torque demand, and a state of at least one of the first and second starter motors.

5. The method of claim 1, wherein the target speed profile is selected from a plurality of engine speed profiles for starting the internal combustion engine, and wherein:

each of the plurality of engine speed profiles includes a plurality of operating characteristics including at least two or more of a starting duration, an entry acceleration, a mid-way speed, an exit acceleration, and the target speed; and

at least one of the operating characteristics differs for each of the engine speed profiles.

6. The method of claim 1, wherein the target speed includes a first threshold.

7. The method of claim 6, wherein the target speed includes a second threshold that is greater than the first threshold.

8. The method of claim 1, wherein selecting the target speed profile includes determining at least one of a starting failure probability, a starting duration, a peak torque required to start the engine, and noise and vibration of the engine during starting.

9. The method of claim 1, wherein selecting the target speed profile includes determining at least one of a peak torque of the first and second starter motors, a peak power of the first and second starter motors, a maximum discharge current of a respective one of the low voltage energy storage device and the high voltage energy storage device, and an available state-of-charge of a respective one of the low voltage energy storage device and the high voltage energy storage device.

10. A method, comprising:

operating a vehicle with a powertrain to satisfy a driver torque demand, and while operating the vehicle;

selecting a target engine speed profile with a controller of the vehicle, wherein selecting the target speed profile includes interpreting operator inputs and operating parameters of the vehicle with the controller to determine the target speed profile, wherein the operating parameters include a charge condition of at least one of a low voltage energy storage device connected to a first starter motor and of a high voltage energy storage device connected to a second starter motor, and wherein selecting target engine speed profile includes selecting one of the first starter motor and the second starter motor in response to the charge condition;

providing a control command to the selected one of the first starter motor and the second starter motor to drive the internal combustion engine according to the target speed profile over a starting duration;

determining the instantaneous engine speed during the starting duration;

modifying the control command during the starting duration to regulate the speed of the internal combustion engine to substantially conform with the target speed profile based on the instantaneous speed determination; and

fueling the internal combustion engine when an actual speed of the internal combustion engine is within a region around a first threshold target speed of the target speed profile.

11. The method of claim 10, wherein:

the second starter motor is an electromechanical device of the power train;

the electromechanical device is selectively engageable to the internal combustion engine with a friction clutch; and

the electromechanical device is operable to satisfy the driver torque demand in an electric drive mode.

12. The method of claim 10, wherein the first starter motor is a starter connected to the powertrain with a gearbox.

13. The method of claim 10, wherein the first starter motor is connected to the powertrain with a gearbox and the second starter motor is an electromechanical device selectively coupled to the internal combustion engine with a friction clutch.

14. A system, comprising:

a powertrain including an internal combustion engine having an output shaft;

a first starter motor operable to rotate the output shaft of the internal combustion engine during starting of the internal combustion engine, wherein the first starter motor is connected to a low voltage energy storage device;

a second starter motor operable to rotate the output shaft of the internal combustion engine during starting of the internal combustion engine, wherein the second starter motor is connected to a high voltage energy storage device;

a controller in communication with the internal combustion engine and the first and second starter motors configured to initiate starting of the internal combustion engine, the controller being configured to;

determine a charge condition of the low voltage energy storage device and the high voltage energy storage device;

select one of the first starter motor and the second starter motor in response to the charge condition;

determine a target speed profile for starting the internal combustion engine with the selected one of the first starter motor and the second starter motor in response to operator inputs and operating parameters of the internal combustion engine; and

determine a control command for the selected one of the first and second starter motors to rotate the output shaft of the internal combustion engine in response to the selected target speed profile and regulate the control command over a starting duration in response to an instantaneous engine speed determination to substantially conform the speed of the internal combustion engine with the target speed profile during the starting duration.

15. The system of claim 14, wherein the second starter motor includes an electromechanical device selectively coupled to output shaft of the internal combustion engine with a friction clutch, wherein the internal combustion engine and the electromechanical device are each operable to satisfy an operator torque demand.

16. The system of claim 15, wherein the second starter motor includes a starter connected to the output shaft of the internal combustion engine with a gearbox.

17. The system of claim 16, wherein the electromechanical device is a motor-generator.

18. The system of claim 14, wherein the first starter motor includes a starter connected to the output shaft of the internal combustion engine with a gearbox.

19. The system of claim 14, wherein the target speed profile is selected from a plurality of engine speed profiles stored in the controller for starting the internal combustion engine, and wherein:

each of the plurality of engine speed profiles includes a plurality of operating characteristics including at least two or more of a starting duration, an entry acceleration, a mid-way speed, an exit acceleration, and the target speed; and

at least one of the operating characteristics differs for each of the engine speed profiles.

20. The system of claim 14, wherein the controller is configured to select the target speed profile by interpreting at least one of a starting failure probability, a starting duration, a peak torque required to start the engine, noise and vibration of the engine during starting, a peak torque of the first and second starter motors, and a peak power of the first and second starter motors.