Method for improving fuel economy in hybrid vehicles

• US 7,240,750 B2
• Filed: 07/22/2005
• Issued: 07/10/2007
• Est. Priority Date: 07/22/2005
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Patel, Vipul M.
• Primary Examiner(s): Phan; Hau
• Application Number:
  US11/187,494
• Publication Number:
  US 20070017719A1
• Time in Patent Office: 718 Days
• Field of Search: 180/65.1, 180/65.2, 180/65.3, 180/65.4, 235/61.J, 731/14, 318/139, 318/430, 702/60, 702/64, 701/35, 701/1, 701/123
• US Class Current: 180/65.265
• 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 20/11 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 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 30/188 Controlling power parameters of the driveline, e.g. determining the required power
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

The present invention provides a method for improving fuel economy in hybrid vehicles. More precisely, the method of the present invention includes a selectable “learn mode” in which the vehicle can learn a particular driving schedule. After a particular driving schedule is learned, the schedule can be recalled to optimize fuel economy on future trips following the same route. By recalling a learned schedule, the system knows in advance what energy level will be needed and can proactively charge the hybrid vehicle'"'"'s battery to an appropriate level.

Claims

1. A method for improving fuel efficiency of a hybrid vehicle having an engine, a battery and an electric motor/generator, the method comprising:

recording energy demand data of the hybrid vehicle during a first trip along a particular driving schedule; and

utilizing the recorded energy demand data to minimize utilization of the engine and maximize utilization of the electric motor/generator during a subsequent trip along the driving schedule by determining whether a current energy demand exceeds the recorded energy demand during the subsequent trip along the driving schedule and waiting a predefined amount of time before activating the engine to charge the battery if the current energy demand is less than the recorded energy demand, such that the fuel efficiency of the hybrid vehicle is improved.

2. The method of claim 1, wherein said utilizing the energy demand data includes anticipating periods of increased energy demand.

3. The method of claim 1 further comprising determining whether an electrical charge on the battery is greater than a predefined charge threshold and activating the electric motor/generator to propel the vehicle if the electrical charge is greater than the a predefined charge threshold.

4. The method of claim 1, wherein said recording energy demand data includes storing the energy demand data at a temporary memory location.

5. The method of claim 1 further comprising saving the energy demand data to a non-volatile memory location.

6. The method of claim 1 further comprising determining whether a recall mode has been initiated prior to recalling the energy demand data.

7. A method for improving fuel efficiency of a hybrid vehicle having an engine, a battery and an electric motor/generator, the method comprising:

recording energy demand data of the hybrid vehicle during a first trip along a particular driving schedule;

recalling the energy demand data prior to a subsequent trip along the driving schedule;

evaluating the energy demand data to anticipate periods of increased energy demand that require operation of the engine; and

coordinating the charging of the battery with the periods of increased energy demand to minimize implementation of the engine such that the fuel efficiency of the hybrid vehicle is improved by determining whether a current energy demand exceeds the recorded energy demand during the subsequent trip along the driving schedule and waiting a predefined amount of time before activating the engine to charge the battery if the current energy demand is less than the recorded energy demand.

8. The method of claim 7 further comprising determining whether a learn mode has been initiated prior to said recording energy demand data.

9. The method of claim 7, wherein said recording energy demand data includes storing the energy demand data at a temporary memory location.

10. The method of claim 7 further comprising saving the energy demand data to a non-volatile memory location.

11. The method of claim 7 further comprising determining whether a recall mode has been initiated prior to said recalling the energy demand data.

12. A method for improving fuel efficiency of a hybrid vehicle having an engine, a battery and an electric motor/generator, the method comprising:

determining whether a learn mode has been initiated;

recording energy demand data of the hybrid vehicle during a first trip along a particular driving schedule if said learn mode has been initiated;

determining whether a recall mode has been initiated;

recalling the energy demand data prior to a subsequent trip along the driving schedule if said recall mode has been initiated;

evaluating the energy demand data to anticipate periods of increased energy demand that require operation of the engine; and

coordinating the charging of the battery with the periods of increased energy demand to minimize implementation of the engine such that the fuel efficiency of the hybrid vehicle is improved by determining whether a current energy demand exceeds the recorded energy demand during the subsequent trip along the driving schedule and waiting a predefined amount of time before activating the engine to charge the battery if the current energy demand is less than the recorded energy demand.

13. The method of claim 12, wherein said recording energy demand data includes storing the energy demand data at a temporary memory location.

14. The method of claim 12 further comprising saving the energy demand data to a non-volatile memory location.