Control architecture and method for one-dimensional optimization of input torque and motor torque in fixed gear for a hybrid powertrain system

• US 7,988,591 B2
• Filed: 09/11/2007
• Issued: 08/02/2011
• Est. Priority Date: 09/11/2007
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Heap, Anthony H.
• Primary Examiner(s): YOUNG, EDWIN
• Application Number:
  US11/853,092
• Publication Number:
  US 20090069148A1
• Time in Patent Office: 1,421 Days
• Field of Search: 477/3, 477/5, 477/902
• US Class Current: 477/3
• 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: 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 20/11 using model predictive control [MPC] strategies, i.e. control methods based on models predicting performance utilising navigation and traffic information in the control strategy B60W20/12
• CPC Class Codes: B60W 2050/0004 In digital systems, e.g. discrete-time systems involving sampling
• CPC Class Codes: B60W 2050/0013 Optimal controllers
• CPC Class Codes: B60W 2555/20 Ambient conditions, e.g. wind or rain
• CPC Class Codes: B60W 50/00 Details of control systems for road vehicle drive control not related to the control of a particular sub-unit , e.g. process diagnostic or vehicle driver interfaces
• 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 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 10/84 Data processing systems or methods, management, administration
• CPC Class Codes: Y10S 477/902 Control signal is engine parameter other than manifold pressure or fuel control

Abstract

There is provided a control system for a powertrain system including an electro-mechanical transmission operative in a plurality of fixed gear modes and continuously variable modes. The control system is adapted to identify preferred operating conditions for operating the powertrain in a fixed gear operating range state. The method comprises determining a range of permissible input torques. States for input torque are iteratively selected, and a motor torque output from the first electrical machine is optimized based upon the selected state for the input torque. A motor torque output from the second electrical machine is determined based upon the optimized motor torque output from the first electrical machine. A cost for each of the iteratively selected states for the input torque and the motor torques from the first and second electrical machines is calculated. A preferred operating range is identified based upon the plurality of costs.

Claims

1. Method for operating a powertrain comprising an internal combustion engine and first and second electrical machines and an electro-mechanical transmission selectively operative to transmit torque therebetween, the method comprising:

determining a range of permissible input torques from the internal combustion engine to the electro-mechanical transmission;

iteratively selecting states for input torque from the range of permissible torques;

optimizing a motor torque output from the first electrical machine based upon the selected state for the input torque;

determining a motor torque output from the second electrical machine based upon the optimized motor torque output from the first electrical machine;

calculating a cost for each of the iteratively selected states for the input torque and the motor torques from the first and second electrical machines; and

,

identifying a preferred input torque based upon the plurality of costs.

2. The method of claim 1, wherein identifying the preferred input torque based upon the plurality of costs comprises identifying a state value for input torque which expends a minimum cost.

3. The method of claim 1, further comprising determining ranges of permissible motor torques from each of the first and second electrical machines based upon the range of permissible input torques.

4. The method of claim 3, wherein the ranges of permissible motor torques from each of the first and second electrical machines are determined based upon available battery power.

5. The method of claim 1, wherein the range of permissible input torques is determined based upon an output speed of the transmission and an operator torque request.

6. The method of claim 1, further comprising determining a preferred operating range state based upon the preferred input torque.

7. The method of claim 1, wherein iteratively selecting state values for the input torque comprises:

executing a one-dimensional search engine to generate state values for the input torque within the range of permissible input torques.

8. The method of claim 1, wherein each cost is calculated based upon engine fuel consumption and an electrical battery power cost associated with the input torque and the motor torques for the first and second electrical machines.

9. The method of claim 1, further comprising operating the electro-mechanical transmission of the powertrain in a fixed gear operating range state.

10. The method of claim 9, further comprising identifying a preferred fixed gear operating range state based upon the plurality of costs.

11. The method of claim 1, wherein optimizing the motor torque output from the first electrical machine based upon the selected state for the input torque comprises selecting the motor torque output from the first electrical machine based upon the selected state for the input torque to minimize battery power to operate the first and second electrical machines.

12. Method to identify preferred operating conditions for operating a powertrain in a fixed gear operating range state the powertrain comprising an internal combustion engine and first and second electrical machines and an electro-mechanical transmission selectively operative to transmit torque therebetween, the method comprising:

determining a range of permissible input torques;

determining a plurality of costs, each cost based upon a selected permissible input torque; and

,

identifying a preferred input torque based upon the plurality of costs.

13. The method of claim 12, further comprising identifying the preferred operating conditions for operating the powertrain in the fixed gear operating range state to substantially meet an operator torque request.

14. The method of claim 12, wherein determining the plurality of costs, each cost based upon a selected permissible input torque further comprises:

iteratively selecting state values for input torque from the range of permissible input torques;

determining an optimum motor torque from the first electrical machine based upon each of the selected state values for the input torque;

determining a motor torque from the second electrical machine based upon the selected state value for the input torque and the optimum motor torque from the first electrical machine; and

,

determining a cost for each iteratively selected state value for the input torque, the optimum motor torque from the first electrical machine, and, the motor torque from the second electrical machine determined therefrom.

15. The method of claim 14, wherein iteratively selecting state values for the input torque comprises:

executing a one-dimensional search engine to generate the state values for the input torque across the range of permissible input torques.

16. The method of claim 14, wherein determining the motor torque from the second electrical machine comprises executing a system equation based upon the selected state value for the input torque and the selected state value for the optimum motor torque from the first electrical machine.

17. The method of claim 14, further comprising determining the optimum motor torque from the first electrical machine based upon each of the selected state values for the input torque to minimize battery power to operate the first and second electrical machines.

18. Apparatus, comprising:

a distributed control module architecture comprising;

a plurality of control modules operatively connected to a powertrain comprising an internal combustion engine and first and second electrical machines and an electro-mechanical transmission selectively operative to transmit torque therebetween the transmission selectively operative in one of a plurality of fixed gear operating range states through selective actuation of a plurality of torque-transfer clutches;

the control modules adapted to execute a plurality of algorithms contained therein to effect the following steps, the algorithms comprising;

code to determine a range of permissible input torques from the internal combustion engine to the electro-mechanical transmission;

code to iteratively select states for input torque from the range of permissible torques;

code to optimize a motor torque output from the first electrical machine based upon the selected state for the input torque;

code to determine a motor torque output from the second electrical machine based upon the optimized motor torque output from the first electrical machine;

code to calculate a cost for each of the iteratively selected states for the input torque and the motor torques from the first and second electrical machines;

code to identify a preferred input torque based upon the plurality of costs; and

, code to select a preferred fixed gear operating range state.

19. The apparatus of claim 18, wherein code to optimize the motor torque output from the first electrical machine based upon the selected state for the input torque comprises code to select the motor torque output from the first electrical machine based upon the selected state for the input torque to minimize battery power to operate the first and second electrical machines.

20. The apparatus of claim 18, wherein the code to iteratively select state values for the input torque comprises:

code to execute a one-dimensional search engine to generate state values for the input torque within the range of permissible input torques.