Fuel consumption control for charge depletion hybrid electric vehicles

• US 6,116,363 A
• Filed: 04/21/1998
• Issued: 09/12/2000
• Est. Priority Date: 05/31/1995
• Status: Expired due to Term

• Current Assignee: Andrew A. Frank
• Original Assignee: Frank Transportation Technology, LLC
• Inventors: Frank, Andrew A.
• Primary Examiner(s): MAR, MICHAEL Y
• Application Number:
  US09/063,995
• Time in Patent Office: 875 Days
• Field of Search: 180/65.1, 180/65.2, 180/65.3, 180/65.4, 180/65.8, 318/587, 701/22, 701/36
• US Class Current: 180/65.25
• CPC Class Codes: B60K 26/02 of initiating means or elements
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/54 Transmission for changing ratio
• CPC Class Codes: B60L 50/62 charged by low-power generators primarily intended to support the batteries, e.g. range extenders
• CPC Class Codes: B60T 13/586 the retarders being of the electric type
• CPC Class Codes: B60T 7/042 by electrical means, e.g. using travel or force sensors
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• 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 10/10 including control of change-speed gearings
• 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 2510/244 Charge state
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2530/13 Mileage
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/103 Accelerator thresholds, e.g. kickdown
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• 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: Y10S 903/917 : with transmission for changing gear ratio
• CPC Class Codes: Y10S 903/945 : Characterized by control of gearing, e.g. control of transmission ratio
• CPC Class Codes: Y10S 903/946 : Characterized by control of driveline clutch

Abstract

A charge depletion method and apparatus for operating the electric motor and auxiliary power unit, such as an internal combustion engine, in a hybrid electric vehicle (HEV) separately or together depending upon the driving conditions. Operation of the electric motor and auxiliary power unit are coordinated as a function of a control policy for the auxiliary power unit based on desired least fuel consumption and/or vehicle emissions characteristics.

Claims

1. An apparatus for controlling operation of a hybrid powered vehicle having an electric motor, a battery powering said electric motor, and an auxiliary power unit, comprising:

(a) means for sensing the speed of the vehicle;

(b) means sensing the depth of discharge of the battery;

(c) means, at vehicle speeds above a threshold speed, for activating said auxiliary power unit to power said vehicle and for using said electric motor to supplement said auxiliary power unit when required;

(e) means, at vehicle speeds below said threshold speed, for deactivating said auxiliary power unit and using said electric motor to power said vehicle;

(f) means for dynamically adjusting said threshold speed as a function of said depth of discharge, wherein said threshold speed and adjustment of said threshold speed are a function of a control policy for said auxiliary power unit based on desired fuel consumption and/or vehicle emissions characteristics.

2. A control apparatus for a hybrid powered vehicle having an electric motor, a battery powering the electric motor, and an auxiliary power unit, comprising:

(a) means for sensing the speed of the vehicle;

(b) means for sensing the depth of discharge of the battery;

(c) means for, at vehicle speeds above a first threshold speed, activating the auxiliary power unit to power the vehicle and using the electric motor to supplement the auxiliary power unit when required;

(d) means for, at vehicle speeds below a second threshold speed, deactivating the auxiliary power unit and using the electric motor to power the vehicle;

(f) means for dynamically adjusting said first and second threshold speeds as a function of said depth of discharge, wherein said threshold speeds and adjustment of said threshold speeds are a function of a control policy for said auxiliary power unit based on desired fuel consumption and/or vehicle emissions characteristics.

3. A method of controlling the operation of a hybrid electric vehicle having an electric motor, a battery powering the electric motor, and an auxiliary power unit, comprising the steps of:

(a) sensing the speed of the vehicle;

(b) sensing the depth of discharge of the battery;

(c) at vehicle speeds above a threshold speed, activating the auxiliary power unit to power the vehicle and using the electric motor to supplement the auxiliary power unit when required;

(d) at vehicle speeds below the threshold speed, deactivating the auxiliary power unit and using the electric motor to power the vehicle; and

(e) dynamically adjusting the threshold speed as a function of said depth of discharge, wherein said threshold speed and adjustment of said threshold speed are a function of a control policy for said auxiliary power unit based on desired fuel consumption and/or vehicle emissions characteristics.

4. A method of operating a hybrid electric vehicle having an electric motor, a battery powering the electric motor, and an auxiliary power unit, comprising the steps of:

(a) sensing the speed of the vehicle;

(b) sensing the depth of discharge of the battery;

(c) at vehicle speeds above a first threshold speed, activating the auxiliary power unit to power the vehicle and using the electric motor to supplement the auxiliary power unit when required;

(d) at vehicle speeds below a second threshold speed, deactivating the auxiliary power unit and using the electric motor to power the vehicle; and

(e) dynamically adjusting said first and second threshold speeds as a function of said depth of discharge, wherein said threshold speeds and adjustment of said threshold speeds are a function of a control policy for said auxiliary power unit based on desired fuel consumption and/or vehicle emissions characteristics.

5. A method of controlling the operation of a hybrid electric vehicle having an electric motor, a battery powering the electric motor, and an auxiliary power unit, comprising the steps of:

(a) sensing the speed of the vehicle;

(b) sensing the depth of discharge of the battery;

(c) at vehicle speeds above a threshold speed, activating the auxiliary power unit to power the vehicle and using the electric motor to supplement the auxiliary power unit when required; and

(d) at vehicle speeds below the threshold speed, deactivating the auxiliary power unit and using the electric motor to power the vehicle, wherein said battery is charge depleted during operation of said vehicle, wherein charge depletion of said battery is a function of a control policy for said auxiliary power unit based on desired fuel consumption and/or vehicle emissions characteristics.

6. A method of controlling the operation of a hybrid electric vehicle having an electric motor, a battery powering the electric motor, and an auxiliary power unit, comprising the steps of:

(a) sensing the speed of the vehicle;

(b) sensing the depth of discharge of the battery;

(c) at vehicle speeds above a threshold speed, activating the auxiliary power unit to power the vehicle and using the electric motor to supplement the auxiliary power unit when required;

(d) at vehicle speeds below the threshold speed, deactivating the auxiliary power unit and using the electric motor to power the vehicle; and

(e) dynamically reducing the threshold speed as the depth of discharge increases, wherein the charge on said battery is depleted by operation of said electric motor and wherein said battery is not recharged by said auxiliary power unit during operation of said vehicle, wherein said threshold speed and adjustment of said threshold speed are a function of a control policy for said auxiliary power unit based on desired fuel consumption and/or vehicle emissions characteristics.