METHOD FOR CONTROLLING THE OPERATING CHARACTERISTICS OF A HYBRID ELECTRIC VEHICLE

• US 20090044996A1
• Filed: 08/05/2008
• Published: 02/19/2009
• Est. Priority Date: 01/03/2001
• Status: Abandoned Application

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Frank, Andrew A.
• Application Number:
  US12/186,480
• Publication Number:
  US 20090044996A1
• Time in Patent Office: Days
• US Class Current: 180/65.290
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/54 Transmission for changing ratio
• CPC Class Codes: B60K 6/543 the transmission being a continuously variable transmission
• 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 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: H02J 7/1446 in response to parameters of a vehicle
• 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 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

Abstract

A control method for operating internal combustion engine electric hybrid vehicles with smaller battery packs, particularly in configurations where an electric motor (E/M) or electric motor/generator (E/MG), a battery, and associated controls are inserted between the engine and a continuously variable or automatic transmission. The interaction between the combustion engine and battery operated electric motor is controlled by taking energy into the batteries only if it is more efficient than throttling the engine and operating the engine at a lower efficiency. Additionally, the batteries are charged to a certain state or the batteries are maintained at a particular state of charge. A goal of the invention is to obtain the best possible fuel economy while maintaining good driveability.

Claims

1. In a hybrid electric vehicle having an internal combustion engine, an electric motor, and a battery system for powering the electric motor, the improvement comprising:

setting a desired depth of discharge of the battery system as a function of average operating speed;

applying an engine “

turn-on”

signal derived from average operating speed to regulate depth of discharge of the battery system by observing average depth of discharge of the battery system over a period of time compared to the desired depth of discharge;

measuring a driver'"'"'s accelerator pedal usage; and

charging said battery system as a function of said accelerator pedal usage.

2. A battery control method for an hybrid electric vehicle having an internal combustion engine, an electric motor, and a battery system for powering the electric motor, comprising:

setting a desired maximum and minimum depth of discharge of the battery system as a function of average operating speed;

applying an engine “

turn-on”

signal derived from average operating speed to regulate depth of discharge of the battery system by observing average depth of discharge of the battery system over a period of time and maintaining the depth of discharge between the desired maximum and minimum with the engine;

measuring a driver'"'"'s accelerator pedal usage; and

charging said battery system as a function of said accelerator pedal usage.

3. A battery control apparatus for a hybrid electric vehicle having an internal combustion engine, an electric motor, and a battery system for powering the electric motor, comprising:

a computer;

programming associated with said computer for

(i) setting a desired maximum and minimum depth of discharge of the battery system as a function of average operating speed;

(ii) applying an engine “

turn-on”

signal derived from average operating speed to regulate the depth of discharge of the battery system by observing average depth of discharge of the battery system over a period of time and maintaining the depth of discharge between the desired maximum and minimum with the engine;

(iii) measuring a driver'"'"'s accelerator pedal usage; and

(iv) charging said battery system as a function of said accelerator pedal usage.