Method, apparatus, signals, and medium for managing power in a hybrid vehicle

• US 7,826,939 B2
• Filed: 09/01/2006
• Issued: 11/02/2010
• Est. Priority Date: 09/01/2006
• Status: Active Grant

• Current Assignee: GE Hybrid Technologies, LLC
• Original Assignee: Azure Dynamics Incorporated
• Inventors: Liu, Wei, Bouchon, Nicolas Louis
• Primary Examiner(s): Tran; Dalena
• Application Number:
  US11/515,175
• Publication Number:
  US 20080059013A1
• Time in Patent Office: 1,523 Days
• Field of Search: 701/22, 180/65.1, 180/65.3, 180/69.4, 290/40.A, 290/40.B, 290/40.C, 290/40.R, 290/38.R, 290/45, 290/46, 318/8, 318/9, 318/34, 318/51, 318/52
• US Class Current: 701/22
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/14 Acceleration
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/425 Temperature
• CPC Class Codes: B60L 2240/427 Voltage
• CPC Class Codes: B60L 2240/429 Current
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60L 2240/507 Operating parameters
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/40 : using propulsion power supplied by capacitors
• CPC Class Codes: B60L 58/15 : Preventing overcharging
• CPC Class Codes: B60L 7/18 : Controlling the braking effect B60L7/12, B60L7/14, B60L7/16 take precedence
• 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 10/26 : for electrical energy, e.g. batteries or capacitors
• 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 20/10 : Controlling the power contribution of each of the prime movers to meet required power demand
• 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 2050/0025 : Transfer function weighting factor
• CPC Class Codes: B60W 2510/0623 : Fuel flow rate
• CPC Class Codes: B60W 2510/244 : Charge state
• CPC Class Codes: B60W 2520/10 : Longitudinal speed
• CPC Class Codes: B60W 2520/105 : Longitudinal acceleration
• CPC Class Codes: F02D 29/02 : peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
• 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 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• 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 903/903 : having energy storing means, e.g. battery, capacitor

Abstract

A method and apparatus for managing power in a hybrid vehicle is disclosed. The vehicle includes an engine, an electric motor, and an energy storage element coupled to the motor. The method involves receiving a request to supply operating power to drive the vehicle and responding to the request by selecting an apportionment of operating power between the engine and the motor from among a plurality of apportionments having respective operating costs such that the selected apportionment is associated with a minimum operating cost, the operating cost including at least an engine fuel consumption cost and a storage element lifetime cost. The method further involves causing power to be supplied by at least one of the engine and the motor in accordance with the selected apportionment.

Claims

1. A method for managing power in a hybrid vehicle, the vehicle comprising an engine, an electric motor, and an energy storage element coupled to the motor, the method comprising:

receiving a request to supply operating power to drive the vehicle;

for each of a plurality of apportionments of operating power between the engine and the motor, producing operating cost values for at least an engine fuel consumption cost and a storage element lifetime cost and combining said operating cost values to produce an overall operating cost;

selecting an apportionment of operating power between the engine and the motor from among the plurality of apportionments, such that said selected apportionment is associated with a minimum operating cost; and

causing power to be supplied by at least one of the engine and the motor in accordance with said selected apportionment.

2. The method of claim 1 further comprising assigning a relative weighting between said engine fuel consumption cost and said storage element lifetime cost, said relative weighting assigned in accordance with fuel prices and storage element replacement prices.

3. The method of claim 1 wherein said motor is operably configured to receive mechanical power and to generate electrical energy for charging the storage element, said mechanical power being produced while reducing or maintaining a speed of the vehicle, and further comprising reducing said operating costs in proportion to a quantity of said electrical energy generated while reducing or maintaining the speed of the vehicle.

4. The method of claim 1 wherein causing power to be supplied comprises producing an engine power control signal and a motor power control signal in response to at least one of a drive signal representing an operator requested power received from an operator input device and a current vehicle operating condition, said power control signals being operable to cause a least one of the engine and the motor to supply power in accordance with said selected apportionment.

5. The method of claim 4 wherein producing said power control signals comprises producing power request signals in response to at least one of:

a current speed of the vehicle; and

a current acceleration of the vehicle.

6. The method of claim 1 wherein combining said operating cost values comprises producing a sum of said operating cost values.

7. The method of claim 1 further comprising storing information representing said plurality of engine fuel consumption costs in a computer memory and wherein producing said engine fuel consumption cost comprises locating an engine fuel consumption cost corresponding to each of said plurality of apportionments of said requested operating power in said memory.

8. The method of claim 7 wherein said locating comprises locating an engine fuel consumption cost corresponding to an engine torque and engine speed that satisfies each of said apportionments of said requested operating power.

9. The method of claim 8 further comprising producing a signal representing an operating temperature of the engine and wherein said locating comprises locating an engine fuel consumption cost corresponding to said operating temperature.

10. The method of claim 7 further comprising producing a signal representing an actual fuel consumption of the engine while operating the vehicle and updating said fuel consumption information stored in said memory in accordance with said actual fuel consumption of the engine.

11. The method of claim 1 wherein producing said operating cost values for said engine fuel consumption cost comprises producing a fuel consumption cost for each of said plurality of apportionments, said fuel consumption cost comprising:

a fuel consumption cost associated with operating the engine to supply said apportionment of power; and

a fuel consumption cost associated with operating the engine to replace energy supplied by the storage element to operate the motor to supply said apportionment of power.

12. The method of claim 11 wherein producing said fuel consumption cost to replace energy supplied by the storage element comprises producing a prediction of a quantity of electrical energy required to replace said energy supplied by the storage element.

13. The method of claim 12 further comprising storing information representing a plurality of engine fuel consumption costs in a computer memory and wherein producing said fuel consumption cost to replace energy supplied by the storage element comprises locating, in said memory, an engine fuel consumption cost corresponding to a minimum engine fuel consumption for replacing said quantity of electrical energy supplied to the motor by the storage element.

14. The method of claim 12 wherein producing said prediction of said quantity of electrical energy comprises predicting a quantity of electrical energy associated with at least one of:

a discharge energy loss in the storage element when supplying said quantity of electrical energy to the motor;

a motor energy loss when supplying said apportionment of said requested operating power to the vehicle; and

a charging energy loss of the storage element when replacing said quantity of electrical energy in the storage element.

15. The method of claim 1 wherein the storage element has a desired state of charge and wherein producing said operating cost values for said storage element lifetime cost comprises producing a storage element lifetime cost proportional to an expected deviation from said desired state of charge associated with operating at each of said plurality of apportionments of said requested operating power.

16. The method of claim 15 further comprising producing a state of charge signal representing a state of charge of the storage element, said lifetime cost for each apportionment being proportional to an absolute value of a difference between said apportionment and a quantity of power required to return the state of charge of the storage element to said desired state of charge.

17. The method of claim 1 wherein producing said operating cost values for said plurality of apportionments of power comprises producing operating costs for apportionments that meet at least one constraint criteria associated with:

an engine maximum power capability;

an engine maximum torque capability;

a motor maximum power capability;

a motor maximum torque capability;

a motor maximum braking power capability;

a motor maximum braking torque capability;

a storage element maximum discharge power; and

a storage element maximum charging power.

18. The method of claim 1 wherein selecting said apportionment comprises selecting an apportionment having a minimum operating cost using a golden section search technique.

19. An apparatus for managing power in a hybrid vehicle, the vehicle comprising an engine, an electric motor, and an energy storage element coupled to the motor, the apparatus comprising:

a processor circuit operably configured to receive a request to supply operating power to drive the vehicle and for each of a plurality of apportionments of operating power between the engine and the motor, to produce operating cost values for at least an engine fuel consumption cost and a storage element lifetime cost and to combine said operating cost values to produce an overall operating cost;

said processor circuit being operably configured select an apportionment of operating power between the engine and the motor from among the plurality of apportionments such that said selected apportionment is associated with a minimum operating cost; and

said processor circuit being operably configured to cause power to be supplied by at least one of the engine and the motor in accordance with said selected apportionment.

20. The apparatus of claim 19 wherein said processor circuit is operably configured to assign a relative weighting between said engine fuel consumption cost and said storage element lifetime cost, said relative weighting assigned in accordance with fuel prices and storage element replacement prices.

21. The apparatus of claim 19 wherein said motor is operably configured to receive mechanical power and to generate electrical energy for charging the storage element, said mechanical power being produced while reducing or maintaining a speed of the vehicle, said processor circuit being operably configured to reduce said operating costs in proportion to a quantity of said electrical energy generated while reducing or maintaining the speed of the vehicle.

22. The apparatus of claim 19 wherein said processor circuit is operably configured to produce an engine power control signal and a motor power control signal in response to said request, said request comprising at least one of a drive signal representing an operator requested power received from an operator input device and a current vehicle operating condition, said power control signals being operable to cause at least one of the engine and the motor to supply power in accordance with said selected apportionment.

23. The apparatus of claim 22 wherein said current vehicle operating condition comprises at least one of:

a current speed of the vehicle; and

a current acceleration of the vehicle.

24. The apparatus of claim 19 wherein said processor circuit is operably configured to combine said operating cost values by producing a sum of said operating cost values.

25. The apparatus of claim 19 wherein said processor circuit comprises a memory operably configured to store information representing said plurality of engine fuel consumption costs therein and wherein said processor circuit is operably configured to locate an engine fuel consumption cost corresponding to each of said plurality of apportionments of said requested operating power in said memory.

26. The apparatus of claim 25 wherein said processor circuit is operably configured to locate an engine fuel consumption cost corresponding to an engine torque and engine speed that satisfies each of said apportionments of said requested operating power.

27. The apparatus of claim 26 further comprising a temperature sensor located on the engine and operable to produce a signal representing an operating temperature of the engine and wherein said processor circuit is operably configured to locate an engine fuel consumption cost corresponding to said operating temperature from said plurality of engine fuel consumption costs.

28. The apparatus of claim 25 further comprising a fuel consumption sensor operable to produce a signal representing an actual fuel consumption of the engine while operating the vehicle and wherein said processor circuit is operably configured to update said fuel consumption information in accordance with said actual fuel consumption of the engine.

29. The apparatus of claim 19 wherein said fuel consumption cost comprises:

a fuel consumption cost associated with operating the engine to supply said apportionment of power; and

a fuel consumption cost associated with operating the engine to replace energy supplied by the storage element to operate the motor to supply said apportionment of power.

30. The apparatus of claim 29 wherein said processor circuit is operably configured to produce a prediction of a quantity of electrical energy required to replace energy supplied by the storage element to operate the motor for each of said plurality of apportionments.

31. The apparatus of claim 30 wherein said processor circuit comprises a memory operably configured to store information representing a plurality of engine fuel consumption costs and wherein said processor circuit is operably configured to locate, in said memory, an engine fuel consumption cost corresponding to a minimum engine fuel consumption for replacing said quantity of electrical energy supplied to the motor by the storage element.

32. The apparatus of claim 30 wherein said prediction of said quantity of electrical energy comprises a prediction of a quantity of electrical energy associated with at least one of:

a discharge energy loss in the storage element when supplying said quantity of electrical energy to the motor;

a motor energy loss when supplying said apportionment of said requested operating power to the vehicle; and

a charging energy loss of the storage element when replacing said quantity of electrical energy in the storage element.

33. The apparatus of claim 19 wherein the storage element has a desired state of charge and wherein said processor circuit is operably configured to produce a storage element lifetime cost proportional to an expected deviation from said desired state of charge associated with operating at each of said plurality of apportionments of said requested operating power.

34. The apparatus of claim 33 wherein said storage element is operably configured to produce a state of charge signal representing a state of charge of the storage element and wherein said processor circuit is operably configured to receive said state of charge signal and to produce said lifetime cost in response to said state of charge signal, said lifetime cost being proportional to an absolute value of a difference between said apportionment and a quantity of power required to return the state of charge of the storage element to said desired state of charge.

35. The apparatus of claim 19 wherein said processor circuit is operably configured to produce operating cost values for apportionments that meet at least one constraint criteria associated with:

an engine maximum power capability;

an engine maximum torque capability;

a motor maximum power capability;

a motor maximum torque capability;

a motor maximum braking power capability;

a motor maximum braking torque capability;

a storage element maximum discharge power; and

a storage element maximum charging power.

36. The apparatus of claim 19 wherein said processor circuit is operably configured to select an apportionment having a minimum operating cost using a golden section search technique.

37. A computer readable medium encoded with codes for directing a processor circuit to carry out a method for managing power in a hybrid vehicle, the vehicle comprising an engine, an electric motor, and an energy storage element coupled to the motor, the method comprising:

receiving a request to supply operating power to drive the vehicle;

for each of a plurality of apportionments of operating power between the engine and the motor, producing operating cost values for at least an engine fuel consumption cost and a storage element lifetime cost and combining said operating cost values to produce an overall operating cost;

selecting an apportionment of operating power between the engine and the motor from among the plurality of apportionments such that said selected apportionment is associated with a minimum operating cost; and

causing power to be supplied by at least one of the engine and the motor in accordance with said selected apportionment.

38. An apparatus for managing power in a hybrid vehicle, the vehicle comprising an engine, an electric motor, and an energy storage element coupled to the motor, the apparatus comprising:

means for receiving a request to supply operating power to drive the vehicle;

means for producing operating cost values for at least an engine fuel consumption cost and a storage element lifetime cost and combining said operating cost values to produce an overall operating cost for each of a plurality of apportionments of operating power between the engine and the motor;

means for selecting an apportionment of operating power between the engine and the motor from among the plurality of apportionments such that said selected apportionment is associated with a minimum operating cost; and

means for causing power to be supplied by at least one of the engine and the motor in accordance with said selected apportionment.

39. The apparatus of claim 38 further comprising means for assigning a relative weighting between said engine fuel consumption cost and said storage element lifetime cost, said relative weighting assigned in accordance with fuel prices and storage element replacement prices.

40. The apparatus of claim 38 wherein said motor is operably configured to receive mechanical power and to generate electrical energy for charging the storage element, said mechanical power being produced while reducing or maintaining a speed of the vehicle and further comprising means for reducing said operating costs in proportion to a quantity of said electrical energy generated while reducing or maintaining the speed of the vehicle.

41. The apparatus of claim 38 wherein said means for causing power to be supplied comprises means for producing an engine power control signal and a motor power control signal in response to at least one of a drive signal representing an operator requested power received from an operator input device and a current vehicle operating condition, said power control signals being operable to cause a least one of the engine and the motor to supply power in accordance with said selected apportionment.

42. The apparatus of claim 41 wherein said means for producing said power control signals comprises means for producing power request signals in response to at least one of:

a current speed of the vehicle; and

a current acceleration of the vehicle.

43. The apparatus of claim 38 wherein said means for combining said operating cost values comprises means for producing a sum of said operating cost values.

44. The apparatus of claim 38 further comprising means for storing information representing said plurality of engine fuel consumption costs and wherein said means for producing said engine fuel consumption cost comprises means for locating an engine fuel consumption cost corresponding to each of said plurality of apportionments of said requested operating power.

45. The apparatus of claim 44 wherein said means for locating comprises means for locating an engine fuel consumption cost corresponding to an engine torque and engine speed that satisfies each of said apportionments of said requested operating power.

46. The apparatus of claim 45 further comprising means for producing a signal representing an operating temperature of the engine and wherein said means for locating comprises means for locating an engine fuel consumption cost corresponding to said operating temperature.

47. The apparatus of claim 44 further comprising means for producing a signal representing an actual fuel consumption of the engine while operating the vehicle and means for updating said stored fuel consumption information in accordance with said actual fuel consumption of the engine.

48. The apparatus of claim 38 wherein said means for producing said operating cost values for said engine fuel consumption cost comprises means for producing a fuel consumption cost for each of said plurality of apportionments, said fuel consumption cost comprising:

a fuel consumption cost associated with operating the engine to supply said apportionment of power; and

a fuel consumption cost associated with operating the engine to replace energy supplied by the storage element to operate the motor to supply said apportionment of power.

49. The apparatus of claim 48 wherein said means for producing said fuel consumption cost to replace energy supplied by the storage element comprises means for producing a prediction of a quantity of electrical energy required to replace said energy supplied by the storage element.

50. The apparatus of claim 49 further comprising means for storing information representing a plurality of engine fuel consumption costs and wherein said means for producing said fuel consumption cost to replace energy supplied by the storage element comprises means for locating, in said means for storing information, an engine fuel consumption cost corresponding to a minimum engine fuel consumption for replacing said quantity of electrical energy supplied to the motor by the storage element.

51. The apparatus of claim 49 wherein said means for producing said prediction of said quantity of electrical energy comprises means for predicting a quantity of electrical energy associated with at least one of:

a discharge energy loss in the storage element when supplying said quantity of electrical energy to the motor;

a motor energy loss when supplying said apportionment of said requested operating power to the vehicle; and

a charging energy loss of the storage element when replacing said quantity of electrical energy in the storage element.

52. The apparatus of claim 38 wherein the storage element has a desired state of charge and wherein said means for producing said operating cost values for said storage element lifetime cost comprises means for producing a storage element lifetime cost proportional to an expected deviation from said desired state of charge associated with operating at each of said plurality of apportionments of said requested operating power.

53. The apparatus of claim 52 further comprising means for producing a state of charge signal representing a state of charge of the storage element, said lifetime cost for each apportionment being proportional to an absolute value of a difference between said apportionment and a quantity of power required to return the state of charge of the storage element to said desired state of charge.

54. The apparatus of claim 38 wherein said means for producing said operating cost values for said plurality of apportionments of power comprises means for producing operating costs for apportionments that meet at least one constraint criteria associated with:

an engine maximum power capability;

an engine maximum torque capability;

a motor maximum power capability;

a motor maximum torque capability;

a motor maximum braking power capability;

a motor maximum braking torque capability;

a storage element maximum discharge power; and

a storage element maximum charging power.

55. The apparatus of claim 38 wherein said means for selecting said apportionment comprises means for selecting an apportionment having a minimum operating cost using a golden section search technique.