Driver Advisory System for Fuel Economy Improvement of a Hybrid Electric Vehicle

• US 20090043467A1
• Filed: 08/09/2007
• Published: 02/12/2009
• Est. Priority Date: 08/09/2007
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Filev, Dimitar Petrov, Syed, Fazal Urrahman
• Granted Patent: US 8,108,136 B2
• Time in Patent Office: Days
• US Class Current: 701/57
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/32 characterised by the fuel cells
• 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 2240/441 Speed
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• 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 2050/0006 Digital architecture hierarchy
• CPC Class Codes: B60W 2050/0031 Mathematical model of the vehicle
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/18 Braking system
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2720/10 Longitudinal speed
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

The invention is an intelligent advisory system, which may be based on fuzzy rule-based logic to guide a vehicle driver in selecting an optimal driving strategy to achieve best fuel economy. The advisory system includes separate controllers for providing advisory information regarding driver demand for power and advisory information regarding vehicle braking, which are conveyed to the driver.

Claims

1. A driver advisory system for a vehicle powertrain having at least one power source, a vehicle driver-controlled vehicle accelerator pedal assembly, a driver-controlled friction brake pedal assembly and a vehicle system controller for controlling power distribution to vehicle traction wheels from the power source;

a power transmission system for delivering power to the traction wheels;

a powertrain controller for controlling delivery of power to the traction wheels through the transmission;

the controller comprising an intelligent system for identifying a current driving pattern for a vehicle driver and for guiding the driver in selecting an optimal driving pattern for current operating conditions and vehicle speed; and

a haptic feedback mechanism forming a part of the accelerator pedal assembly for conveying to the driver a feedback sensory signal for guidance to maximize operating economy of the power source for given operating conditions.

8. The system set forth in claim 1, wherein the controller is a fuzzy rule-based driver advisor controller with an instantaneous fuel economy input, a target fuel economy input and a driver advisory output, the controller being conditioned to develop an accelerator pedal position modifier based on a difference between target fuel economy, rate of change of instantaneous fuel economy and instantaneous engine speed.

9. The driver advisory system set forth in claim 8, wherein the controller in a fuzzy rule-based driver advisory controller has a total vehicle braking input and a regenerative braking input, which determine an uncaptured vehicle braking value, the controller being conditioned to develop a brake pedal position modifier based on the uncaptured braking value.

10. The driver advisory system set forth in claim 8, wherein the controller is further conditioned to integrate the accelerator pedal position modifier with appropriate saturation limits to determine an upper accelerator pedal position limit for a given instantaneous operating condition.

11. The driver advisory system set forth in claim 9, wherein the controller is further conditioned to integrate the brake pedal position modifier with appropriate saturation limits to determine an upper brake pedal position limit for a given instantaneous operating condition.

12. The driver advisory system set forth in claim 1, wherein the haptic feedback mechanism includes means for adjusting the intensity of the accelerator pedal position feedback sensory signal from a default intensity.

2. A driver advisory system for a vehicle powertrain having at least one power source, a vehicle driver-controller vehicle accelerator pedal assembly, a driver-controlled brake pedal assembly and a vehicle system controller for controlling power distribution to vehicle traction wheels from the power source;

a power transmission system for delivering power to the traction wheels;

a powertrain controller for controlling delivery of power from the power source to the traction wheels through the transmission;

the controller comprising an intelligent system for identifying a current driving pattern for a vehicle driver and for guiding the driver in selecting an optimal driving pattern for current operating conditions and vehicle speed;

a first haptic feedback system forming a part of the accelerator pedal assembly for conveying to the driver an acceleration pedal position feedback sensory signal for guidance to maximize operating efficiency of the power source for given operating conditions; and

a second haptic feedback system forming a part of the brake pedal assembly for conveying to the driver a brake pedal position feedback sensory signal for guidance to maximize brake operating efficiency for given operating conditions.

3. The system set forth in claim 2 wherein the powertrain has hybrid electric characteristics with an accelerator pedal controlled engine, an electric motor electrically coupled to a battery and an electric generator;

the transmission having gearing, a first element of the gearing bearing mechanically connected to the engine, a second element of the gearing being mechanically connected to the generator, and a third element being drivably connected to the traction wheels;

the powertrain controller coordinating power delivery through the gearing, whereby engine speed is determined by reaction torque acting on the generator.

13. The driver advisory system set forth in claim 2, wherein the second haptic feedback mechanism includes means for adjusting the intensity of the brake pedal position sensory signal from a default intensity.

4. A method for controlling a hybrid electric vehicle having a powertrain that includes an accelerator pedal controlled internal combustion engine power source and an electric power source that includes an electric motor, an electric generator and an electric battery, the transmission delivering power to vehicle traction wheels from each power source;

the method comprising the steps of;

managing power flow from each power source through the transmission to selectively provide hybrid drive, mechanical drive using solely engine power, electric drive using solely power of the motor, regenerative braking, engine starting and battery power maintenance;

determining an optimum accelerator pedal position for possible operating conditions based upon desired fuel economy and actual instantaneous fuel economy;

determining a fuel economy error;

determining a rate of change of fuel economy error;

determining an accelerator pedal position modifier based on fuel economy error, rate of change of fuel economy error and actual instantaneous engine power; and

integrating the accelerator pedal position modifier within appropriate saturation limits to determine an optimum accelerator pedal position for a driver demand for power for a given instantaneous operating condition, whereby the driver is provided with guidance to improve engine fuel combustion economy.

6. The method set forth in claim 4, wherein the provision of guidance to the driver to improve engine fuel combustion economy includes developing a haptic sensory signal to the driver to indicate when an accelerator pedal position deviates from an optimum position.

5. A method for controlling a hybrid electric vehicle having a powertrain that includes an accelerator pedal controlled internal combustion engine power source and an electric power source that includes an electric motor, an electric generator and an electric battery, the transmission delivering power to vehicle traction wheels from each power source;

the method comprising the steps of;

managing power flow from each power source through the transmission to selectively provide hybrid drive, mechanical drive using solely engine power, electric drive using solely power of the motor, regenerative braking, engine starting and battery power maintenance;

determining an optimum brake pedal position using total braking power and total regenerative power to determine a brake pedal position modifier based on uncaptured braking power and upon whether a desired regenerative braking flag indicates that the capturing of regenerative energy is desired under current vehicle operating conditions; and

integrating the brake pedal position modifier with appropriate saturation limits to determine an optimum brake pedal position, whereby the driver is provided with guidance to improve engine fuel combustion economy by modifying actual brake pedal position to achieve optimum vehicle braking.

7. The method set forth in claim 5, wherein the provision of guidance to the driver to improve engine fuel combustion economy includes developing a haptic sensory signal to the driver to indicate when a brake pedal position deviates from an optimum position.

14. A driver advisory system for a vehicle powertrain having at least one power source, a vehicle driver-controlled vehicle accelerator pedal assembly, a driver-controlled friction brake pedal assembly and a vehicle system controller for controlling power distribution to vehicle traction wheels from the power source;

a power transmission system for delivering power to the traction wheels;

a powertrain controller for controlling delivery of power to the traction wheels through the transmission;

the controller comprising an intelligent system for identifying a current driving pattern for a vehicle driver and for guiding the driver in selecting an optimal driving pattern for current operating conditions and vehicle speed;

means for calculating an upper limit for driver demand for power for given operating conditions; and

a haptic feedback mechanism forming a part of the accelerator pedal assembly for conveying to the driver a feedback sensory signal for guidance to maximize operating economy of the power source for given operating conditions when the driver demand for power exceeds the upper limit.

21. The system set forth in claim 14, wherein the controller is a fuzzy rule-based driver advisor controller with an instantaneous fuel economy input, a target fuel economy input and a driver advisory output, the controller being conditioned to develop an accelerator pedal position modifier based on a difference between target fuel economy, rate of change of instantaneous fuel economy and instantaneous engine speed.

22. The driver advisory system set forth in claim 21, wherein the controller in a fuzzy rule-based driver advisory controller has a total vehicle braking input and a regenerative braking input, which determine an uncaptured vehicle braking value, the controller being conditioned to develop a brake pedal position modifier based on the uncaptured braking value.

23. The driver advisory system set forth in claim 21, wherein the controller is further conditioned to integrate the accelerator pedal position modifier with appropriate saturation limits to determine an upper accelerator pedal position limit for a given instantaneous operating condition.

24. The driver advisory system set forth in claim 21, wherein the controller is further conditioned to integrate the brake pedal position modifier with appropriate saturation limits to determine an upper brake pedal position limit for a given instantaneous operating condition.

25. The driver advisory system set forth in claim 14, wherein the haptic feedback mechanism includes means for adjusting the intensity of the accelerator pedal position feedback sensory signal from a default intensity.

15. A driver advisory system for a vehicle powertrain having at least one power source, a vehicle driver-controller vehicle accelerator pedal assembly, a driver-controlled brake pedal assembly and a vehicle system controller for controlling power distribution to vehicle traction wheels from the power source;

a power transmission system for delivering power to the traction wheels;

a powertrain controller for controlling delivery of power from the power source to the traction wheels through the transmission;

the controller comprising an intelligent system for identifying a current driving pattern for a vehicle driver and for guiding the driver in selecting an optimal driving pattern for current operating conditions and vehicle speed;

means for calculating an upper limit for driver demand for power for current operating conditions;

a first haptic feedback system forming a part of the accelerator pedal assembly for conveying to the driver an acceleration pedal position feedback sensory signal for guidance to maximize operating efficiency of the power source for given operating conditions when the driver demand for power exceeds the upper limit; and

a second haptic feedback system forming a part of the brake pedal assembly for conveying to the driver a brake pedal position feedback sensory signal for guidance to maximize powertrain operating efficiency for given operating conditions.

16. The system set forth in claim 15 wherein the powertrain has hybrid electric characteristics with an accelerator pedal controlled engine, an electric motor electrically coupled to a battery and an electric generator;

the transmission having gearing, a first element of the gearing bearing mechanically connected to the engine, a second element of the gearing being mechanically connected to the generator, and a third element being drivably connected to the traction wheels;

the powertrain controller coordinating power delivery through the gearing, whereby engine speed is determined by reaction torque acting on the generator.

26. The driver advisory system set forth in claim 15, wherein the second haptic feedback mechanism includes means for adjusting the intensity of the brake pedal position sensory signal from a default intensity.

17. A method for controlling a hybrid electric vehicle having a powertrain that includes an accelerator pedal controlled internal combustion engine power source and an electric power source that includes an electric motor, an electric generator and an electric battery, the transmission delivering power to vehicle traction wheels from each power source;

the method comprising the steps of;

managing power flow from each power source through the transmission to selectively provide hybrid drive, mechanical drive using solely engine power, electric drive using solely power of the motor, regenerative braking, engine starting and battery power maintenance;

determining an optimum accelerator pedal position for possible operating conditions based upon desired fuel economy and actual instantaneous fuel economy;

determining a fuel economy error;

determining a rate of change of fuel economy error;

determining an accelerator pedal position modifier based on fuel economy error, rate of change of fuel economy error and actual instantaneous engine power; and

integrating the accelerator pedal position modifier within appropriate saturation limits to determine an accelerator pedal upper position limit for a driver demand for power for a given instantaneous operating condition, whereby the driver is provided with guidance to improve engine fuel combustion economy when the accelerator pedal upper limit is exceeded.

19. The method set forth in claim 17, wherein the provision of guidance to the driver to improve engine fuel combustion economy includes developing a haptic sensory signal to the driver to indicate when an accelerator pedal position deviates from an optimum position.

18. A method for controlling a hybrid electric vehicle having a powertrain that includes an accelerator pedal controlled internal combustion engine power source and an electric power source that includes an electric motor, an electric generator and an electric battery, the transmission delivering power to vehicle traction wheels from each power source;

the method comprising the steps of;

managing power flow from each power source through the transmission to selectively provide hybrid drive, mechanical drive using solely engine power, electric drive using solely power of the motor, regenerative braking, engine starting and battery power maintenance;

determining an optimum brake pedal position using total braking power and total regenerative power to determine a brake pedal position modifier based on uncaptured braking power and upon whether a desired regenerative braking flag indicates that the capturing of regenerative energy is desired under current vehicle operating conditions; and

integrating the brake pedal position modifier with appropriate saturation limits to determine an upper limit for brake pedal position, whereby the driver is provided with guidance to improve powertrain operating efficiency by modifying actual brake pedal position when the brake pedal position upper limit is exceeded.

20. The method set forth in claim 18, wherein the provision of guidance to the driver to improve engine fuel combustion economy includes developing a haptic sensory signal to the driver to indicate when a brake pedal position deviates from an optimum position.