METHOD FOR CONTROLLING A HYBRID POWERTRAIN SYSTEM BASED UPON HYDRAULIC PRESSURE AND CLUTCH REACTIVE TORQUE CAPACITY

• US 20090118935A1
• Filed: 10/15/2008
• Published: 05/07/2009
• Est. Priority Date: 11/05/2007
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG, Daimler AG (Mercedes-Benz Group AG), Chrysler Group LLC (Stellantis NV)
• Original Assignee: BMW AG (Bayerische Motoren Werke AG), Daimler AG (Mercedes-Benz Group AG), GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust), Chrysler LLC (Stellantis NV)
• Inventors: Heap, Anthony H., Sah, Jy-Jen F.
• Granted Patent: US 8,121,768 B2
• Time in Patent Office: Days
• US Class Current: 701/54
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/486 Operating parameters
• 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 10/105 of electric type
• CPC Class Codes: B60W 10/115 with planetary gears
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• 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 20/15 Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/24 Energy storage means
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2540/16 Ratio selector position
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 2710/105 Output torque
• CPC Class Codes: B60W 30/18 : Propelling the vehicle
• CPC Class Codes: F16H 2037/0866 : Power split variators with distributing differentials, with the output of the CVT connected or connectable to the output shaft
• CPC Class Codes: F16H 2037/102 : the input or output shaft of the transmission is connected or connectable to two or more differentials
• CPC Class Codes: F16H 2037/104 : Power split variators with one end of the CVT connected or connectable to two or more differentials
• CPC Class Codes: F16H 2037/106 : with switching means to provide two variator modes or ranges
• CPC Class Codes: Y02T 10/40 : Engine management systems
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 10/84 : Data processing systems or methods, management, administration

Abstract

A powertrain system includes an engine coupled to an electro-mechanical transmission to transfer power between the engine and a plurality of torque generating machines and an output member. The transmission is operative in one of a plurality of operating range states through selective application of torque transfer clutches and the engine is operatively coupled to a main hydraulic pump to supply pressurized fluid to a hydraulic circuit operative to apply the torque transfer clutches. A method for controlling the powertrain system includes determining an output torque request to the output member, determining a pressure output of the main hydraulic pump based upon an engine input speed, calculating a clutch reactive torque capacity for each applied torque transfer clutch based upon the pressure output of the main hydraulic pump, and determining a preferred engine input speed to achieve the clutch reactive torque capacity to meet the output torque request to the output member.

Claims

1. Method for controlling a powertrain system including an engine coupled to an electromechanical transmission to transfer power between the engine and a plurality of torque generating machines and an output member, the transmission operative in one of a plurality of operating range states through selective application of torque transfer clutches and the engine operatively coupled to a main hydraulic pump to supply pressurized fluid to a hydraulic circuit operative to apply the torque transfer clutches, the method comprising:

determining an output torque request to the output member;

determining a pressure output of the main hydraulic pump based upon an engine input speed;

calculating a clutch reactive torque capacity for each applied torque transfer clutch based upon the pressure output of the main hydraulic pump; and

determining a preferred engine input speed to achieve the clutch reactive torque capacity to meet the output torque request to the output member.

2. The method of claim 1, further comprising determining a preferred operating range state for the transmission for the preferred engine input speed to achieve the clutch reactive torque capacity to meet the output torque request to the output member.

3. The method of claim 2, further comprising controlling the engine to the preferred engine input speed and controlling the transmission to the preferred operating range state to achieve the clutch reactive torque capacity to meet the output torque request to the output member.

4. The method of claim 1, further comprising:

determining the output torque request to the output member based upon an operator input to an accelerator pedal;

determining a preferred clutch reactive torque capacity to achieve the output torque request; and

controlling the engine input speed to control the pressure output of the main hydraulic pump to achieve the preferred clutch reactive torque capacity.

5. The method of claim 4, comprising increasing the engine input speed to increase the pressure output of the main hydraulic pump to achieve the clutch reactive torque capacity.

6. The method of claim 1, further comprising

determining the output torque request to the output member based upon an operator input to a brake pedal;

determining a preferred clutch reactive torque to achieve the output torque request;

determining a clutch reactive torque capacity to achieve the preferred clutch reactive torque; and

controlling the engine to the preferred engine input speed to control the pressure output of the main hydraulic pump to achieve the preferred clutch reactive torque capacity.

7. The method of claim 6, comprising maintaining the engine input speed above a threshold to maintain the pressure output of the main hydraulic pump to maintain the clutch reactive torque capacity to achieve regenerative braking.

8. The method of claim 1, further comprising:

executing searches of candidate transmission operating range states based upon the preferred engine input speed and the output torque request to the output member; and

determining preferred motor torques for the torque generating machines based upon the preferred engine input speed and the output torque request to the output member for the candidate transmission operating range states.

9. The method of claim 8, further comprising

determining power costs for the transmission operations of the candidate operating range states based upon the preferred motor torques for the torque generating machines and the preferred engine input speed;

and

selecting a preferred operating range state based upon the power costs.

10. The method of claim 9, wherein the preferred operating range state comprises the candidate operating range state having a minimum power cost.

11. The method of claim 9, further comprising determining a preferred clutch reactive torque to achieve the output torque request;

determining a clutch reactive torque capacity to achieve the preferred clutch reactive torque;

controlling the engine to the preferred engine input speed to control the pressure output of the main hydraulic pump to achieve the preferred clutch reactive torque capacity, and

controlling the transmission to the preferred operating range state.

12. The method of claim 11, further comprising controlling the torque generating machines to the preferred motor torques.

13. Method for controlling a powertrain system including an engine coupled to an electromechanical transmission to transfer power between the engine and a plurality of torque generating machines and an output member, the transmission operative in one of a plurality of operating range states through selective application of torque transfer clutches and the engine operatively coupled to a main hydraulic pump to supply pressurized fluid to a hydraulic circuit operative to apply the torque transfer clutches, the method comprising:

determining an output torque request to the output member;

determining a pressure output of the main hydraulic pump based upon an engine input speed;

calculating a clutch reactive torque capacity for the applied torque transfer clutch based upon the pressure output of the main hydraulic pump; and

controlling the engine to a preferred engine input speed to achieve the clutch reactive torque capacity and controlling the torque generating machines to meet the output torque request to the output member.

14. The method of claim 13, further comprising determining a preferred operating range state for the transmission for the preferred engine input speed to achieve the clutch reactive torque to meet the output torque request to the output member.

15. Method for controlling a powertrain system including a hybrid transmission operative to transfer power between an engine and a torque machine and an output member through application of torque transfer clutches, the engine operatively coupled to a main hydraulic pump to supply pressurized fluid to a hydraulic circuit operative to apply the torque transfer clutches, the method comprising:

determining an output torque request to the output member;

determining a pressure output of the main hydraulic pump based upon an engine input speed;

calculating clutch reactive torque capacity for the applied torque transfer clutch based upon the pressure output of the main hydraulic pump; and

controlling the engine to a preferred engine input speed to achieve the clutch reactive torque capacity and controlling the torque generating machines to meet the output torque request to the output member.