HYBRID VEHICLE AUTO START SYSTEMS AND METHODS

• US 20100038158A1
• Filed: 01/13/2009
• Published: 02/18/2010
• Est. Priority Date: 08/15/2008
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Schwenke, R. Travis, Nicholson, James B, Bryde, Steven G., Whitney, Christopher E., Lahti, John L., Bhattarai, Birendra P., Jin, Ning, Williams, Cheryl A.
• Granted Patent: US 8,157,035 B2
• Time in Patent Office: Days
• US Class Current: 180/65.265
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/486 Operating parameters
• 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 2050/0006 Digital architecture hierarchy
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2510/083 Torque
• CPC Class Codes: B60W 2510/105 Output torque
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2710/0605 Throttle position
• CPC Class Codes: B60W 2710/0616 Position of fuel or air injector
• CPC Class Codes: B60W 2710/0666 : Engine torque
• CPC Class Codes: B60W 2710/083 : Torque
• CPC Class Codes: B60W 30/16 : Control of distance between vehicles, e.g. keeping a distance to preceding vehicle
• CPC Class Codes: B60W 30/18 : Propelling the vehicle
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility

Abstract

A control system for an engine includes an engine control module (ECM) that operates in a first mode and a second mode. The ECM generates an idle speed signal and a transmission load signal that is based on an idle speed of the engine. The hybrid control module (HCM) increases electric motor torque to increase a current speed of the engine based on the idle speed signal and the transmission load signal. The HCM controls the current speed when in the first mode. The ECM controls the current speed when in the second mode. The HCM transfers control of the current speed to the ECM when at least one of the current speed matches the idle speed and a combustion torque output of the engine is equal to a requested crankshaft output torque.

Claims

1. A control system for an engine comprising:

an engine control module (ECM) that operates in a first mode and a second mode and that generates an idle speed signal and a transmission load signal that is based on an idle speed of the engine;

a hybrid control module (HCM) that increases electric motor torque to increase a current speed of the engine based on the idle speed signal and the transmission load signal and that controls the current speed when in the first mode,

wherein the ECM controls the current speed when in the second mode, and

wherein the HCM transfers control of the current speed to the ECM when at least one of the current speed matches the idle speed and a combustion torque output of the engine is equal to a requested crankshaft output torque.

2. The control system of claim 1 further comprising a brake sensor that generates a brake signal,

wherein the ECM and the HCM operate in the first mode and the ECM generates the idle speed signal and the transmission load signal based on the brake signal.

3. The control system of claim 1 further comprising an accelerator sensor that generates an accelerator signal,

wherein the HCM transfers control of the current speed to the ECM before the combustion torque output is equal to the requested crankshaft output torque and before the current speed of the engine is greater than or equal to the idle speed based on the accelerator signal.

4. The control system of claim 1 wherein the ECM controls throttle position of the engine based on at least one of a cranking cylinder event and a coolant temperature.

5. The control system of claim 1 wherein the ECM reduces throttle area when in the first mode to reduce pressures in cylinders of the engine.

6. The control system of claim 1 wherein the HCM adjusts a torque request corresponding to at least one of spark and fuel when in the first mode.

7. The control system of claim 1 wherein the ECM advances spark timing when in the second mode based on a torque request.

8. The control system of claim 1 wherein the ECM estimates torque output of the engine, and

wherein the HCM controls the electric motor torque based on the estimated torque output.

9. The control system of claim 1 wherein the ECM ramps the combustion torque from a friction torque level of the engine to an idle speed torque level that corresponds with a steady state transmission load based on a torque request signal from the HCM.

10. A method of operating an engine control system comprising:

receiving an auto start command signal;

reducing pressures within cylinders of an engine based on the auto start command signal comprising;

receiving a torque request signal corresponding to at least one of spark and fuel;

calculating a powertrain output torque based on engine air flow commands of an engine control module; and

controlling air flow to the engine based on the powertrain output torque;

increasing electric motor torque to a predetermined level to overcome friction and pumping pressures of the engine;

reducing electric motor torque to ramp up a current speed of the engine and to engage a transmission; and

activating and increasing combustion torque of the engine after the current speed of the engine is within a predetermined range of an idle speed and after a manifold absolute pressure of the engine is less than a first predetermined level.

11. The method of claim 10 wherein receiving an auto start command signal comprises at least one of receiving a brake signal, receiving an accelerator signal, receiving an air conditioning activation signal, and receiving a regeneration signal.

12. The method of claim 10 further comprising retarding spark when spark of the engine is enabled.

13. The method of claim 10 wherein reducing pressures within the cylinders of the engine comprises increasing the electric motor torque to increase the current speed.

14. The method of claim 10 wherein fuel to the engine is enabled when the current speed of the engine is greater than or equal to a second predetermined level and based on an accelerator pedal position.

15. The method of claim 14 wherein fuel to the engine is enabled in a normal mode when the manifold absolute pressure of the engine is less than a third predetermined level, and

wherein fuel to the engine is enabled in an aggressive mode when the transmission is engaged based on speed of the engine.

16. The method of claim 10 wherein fuel to the engine is enabled when the engine is activated.

17. The method of claim 10 further comprising transferring control of the current speed from a hybrid control module to an engine control module when at least one of the combustion torque is activated and greater than a second predetermined level and the current speed is greater than or equal to an idle speed.

18. The method of claim 10 wherein air flow to the engine is controlled by an engine control module,

wherein the engine control module pumps down the manifold absolute pressure by adjusting air flow across a throttle to a predetermined air flow level, and then

wherein the engine control module adjusts the air flow across the throttle to provide a requested torque output.

19. The method of claim 10 further comprising increasing combustion torque of the engine to reduce the electric motor torque to zero when control of the current speed of the engine is transferred from a hybrid control module to the engine control module.

20. The method of claim 10 further comprising transferring control of the current speed of the engine after activation of the combustion torque of the engine,

wherein when control of the current speed of the engine is transferred from a hybrid control module to an engine control module a closed loop error of the hybrid control module is maintained at a constant level and is transmitted to the engine control module.

21. The method of claim 10 further comprising wherein the engine control module switches from an idle speed control mode that is controlled by a hybrid control module to a driver torque request mode that is controlled by the engine control module based on an accelerator signal.

22. The method of claim 21 wherein the engine control module controls electric motor torque based on a difference between a crankshaft torque and a WOM torque, where WOM torque is combustion torque of the engine minus brake torque without electric motor torque applied.