Method to compensate for transmission spin loss for a hybrid powertrain system

• US 8,165,777 B2
• Filed: 10/14/2008
• Issued: 04/24/2012
• 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: Bayerische Motoren Werke AG, GM Global Technology Operations LLC (General Motors Company), Daimler AG (Mercedes-Benz Group AG), Chrysler LLC (Stellantis NV)
• Inventors: Heap, Anthony H.
• Primary Examiner(s): Hellner, Mark
• Assistant Examiner(s): Diacou, Ari M.
• Application Number:
  US12/251,439
• Publication Number:
  US 20090118933A1
• Time in Patent Office: 1,288 Days
• Field of Search: 701/54, 701/101, 701/102, 701/108, 701/110, 477/108, 477/110
• US Class Current: 701/102
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/26 characterised by the motors or the generators
• 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: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60W 10/04 including control of propulsion units
• 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 10/115 with planetary gears
• 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 2510/083 Torque
• CPC Class Codes: B60W 2510/1005 Transmission ratio engaged
• CPC Class Codes: B60W 2510/1015 Input shaft speed, e.g. turbine speed
• CPC Class Codes: B60W 2510/1025 Input torque
• CPC Class Codes: B60W 2510/104 Output speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2710/083 : Torque
• CPC Class Codes: B60W 2710/1011 : Input shaft speed, e.g. turbine speed
• CPC Class Codes: B60W 2710/1022 : Input torque
• CPC Class Codes: B60W 2710/1038 : Output speed
• CPC Class Codes: B60W 2710/105 : Output torque
• CPC Class Codes: B60W 50/04 : Monitoring the functioning of the control system
• 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: F16H 3/728 : with means to change ratio in the mechanical gearing
• 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 10/84 : Data processing systems or methods, management, administration

Abstract

A powertrain system includes an engine coupled to an input member of a hybrid transmission. The hybrid transmission is operative to transmit torque between the input member and a torque generating machine and an output member. A method for controlling the powertrain system includes monitoring an operator torque request, determining an output torque command and an output speed of the output member, iteratively selecting candidate input speeds to the input member, determining mechanical power loss in the hybrid transmission for each of the candidate input speeds and the output speed, and selecting a preferred input speed comprising the candidate input speed that achieves a minimum mechanical power loss in the hybrid transmission at the output speed.

Claims

1. Method for controlling a powertrain system including an engine coupled to an input member of a hybrid transmission, the hybrid transmission operative to transmit torque between the input member and a torque generating machine and an output member, the hybrid transmission operative in one of a plurality of operating range states to transfer power between the input member and the torque generating machine and the output member, the method comprising:

monitoring an operator torque request;

determining an output torque command and an output speed of the output member;

selecting candidate operating range states;

iteratively selecting candidate input speeds to the input member for each of the candidate operating range states;

determining mechanical power loss in the hybrid transmission in each of the candidate operating range states for each of the candidate input speeds and the output speed;

selecting a preferred input speed comprising the candidate input speed that achieves a minimum mechanical power loss in the hybrid transmission at the candidate operating range state for each of the selected operating range states at the output speed; and

selecting a preferred operating range state comprising the candidate operating range state having the minimum preferred input speed at the output speed.

2. The method of claim 1, further comprising determining a preferred motor torque command to the torque generating machine based upon the mechanical power loss in the hybrid transmission and the operator torque request.

3. The method of claim 1, further comprising:

selecting a fixed gear operating range state;

determining the candidate input speed for the fixed gear operating range state based upon the output speed of the output member;

determining a mechanical power loss in the hybrid transmission for the candidate input speed;

determining a range of input torque to the hybrid transmission;

executing a search within the range of input torques to the transmission including selecting a candidate input torque,

determining preferred candidate output torque and a candidate motor torque for the torque generative machine associated with the candidate input torque, and

determining a power cost based upon the mechanical power loss for the hybrid transmission operating at the candidate output torque at the candidate input speed; and

selecting a preferred input torque that achieves a minimum power cost.

4. The method of claim 1, further comprising:

selecting a continuously variable operating range state;

determining a range of input speed and a range of input power to the hybrid transmission;

executing a search within the ranges of input speed and input power to the transmission including

selecting a candidate input power and a candidate input speed,

determining a preferred candidate input torque,

determining a candidate motor torque for the torque generative machine based upon the candidate input torque,

determining a power cost based upon the mechanical power loss for the hybrid transmission operating at the candidate output power at the candidate input speed; and

selecting a preferred input speed and input power that achieves a minimum power cost.

5. The method of claim 1, further comprising controlling motor torque output from the torque generating machine to compensate for the mechanical power loss in the hybrid transmission operating at the preferred input speed at the output speed.

6. Method for controlling a powertrain system including an engine coupled to an input member of a hybrid transmission, the hybrid transmission operative to transmit torque between the input member and first and second electric machines and an output member, the hybrid transmission operative in one of a plurality of operating range states to transfer power between the input member and the torque generating machine and the output member, the method comprising:

monitoring an operator torque request;

determining an output torque command and an output speed of the output member;

selecting candidate operating range states;

iteratively selecting candidate input speeds to the input member for each of the candidate operating range states;

determining mechanical power loss in the hybrid transmission in each of the candidate operating range states for each of the candidate input speeds and the output speed;

selecting a preferred input speed comprising the candidate input speed that achieves a minimum mechanical power loss in the hybrid transmission at the candidate operating range state for each of the selected operating range states at the output speed; and

selecting a preferred operating range state comprising the candidate operating range state having the minimum preferred input speed at the output speed.

7. The method of claim 6, further comprising determining preferred motor torque commands to the first and second electric machines based upon the mechanical power loss in the hybrid transmission and the operator torque request.

8. The method of claim 6, further comprising:

selecting a fixed gear operating range state;

determining the candidate input speed for the fixed gear operating range state based upon the output speed of the output member;

determining a mechanical power loss in the hybrid transmission for the candidate input speed;

determining a range of input torque to the hybrid transmission;

executing a search within the range of input torques to the transmission including selecting a candidate input torque,

determining preferred candidate output torque and candidate motor torques for the first and second electric machines associated with the candidate input torque, and

determining a power cost based upon the mechanical power loss for the hybrid transmission operating at the candidate output torque at the candidate input speed; and

selecting a preferred input torque that achieves a minimum power cost.

9. The method of claim 6, further comprising

selecting a continuously variable operating range state;

determining a range of input speed and a range of input power to the hybrid transmission;

executing a search within the ranges of input speed and input power to the transmission including

selecting a candidate input power and a candidate input speed,

determining a preferred candidate input torque,

determining candidate motor torques for the first and second electric machines based upon the candidate input torque,

determining a power cost based upon the mechanical power loss for the hybrid transmission operating at the candidate output power at the candidate input speed; and

selecting a preferred input speed and input power that achieves a minimum power cost.

10. The method of claim 6, further comprising controlling motor torques output from the first and second electric machines to compensate for the mechanical power loss in the hybrid transmission operating at the preferred input speed at the output speed.