Control system for hybrid vehicle

• US 6,127,813 A
• Filed: 03/30/1999
• Issued: 10/03/2000
• Est. Priority Date: 03/31/1998
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Tamagawa, Yutaka
• Primary Examiner(s): PONOMARENKO, NICHOLAS
• Application Number:
  US09/280,707
• Time in Patent Office: 553 Days
• Field of Search: 322/14, 322/15, 322/16, 322/17, 290/40 C, 318/139, 318/140, 318/141
• US Class Current: 322/16
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60L 50/15 with additional electric power supply with capacitors charged by engine-driven generators B60L50/40; with batteries charged by engine-driven generators B60L50/61
• 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 20/30 Control strategies involving selection of transmission gear ratio control of change speed gearings, together with other vehicle sub-units B60W10/10; HEV transmission gearing B60K6/36; gearings and control thereof F16H
• 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 903/945 Characterized by control of gearing, e.g. control of transmission ratio

Abstract

A hybrid vehicle has an engine as a propulsive power unit for the hybrid vehicle, an electric energy storage device for storing electric energy, and a generator motor operable alternatively as an electric motor for generating an assistive output power to be added to an output power generated by the engine, from the electric energy stored by the electric energy storage device, and as an electric generator for regenerating electric energy to be charged into the electric energy storage device. A control system regards an integrated charged quantity which represents an integrated value of electric energy quantity charged from the generator motor into the electric energy storage device when the generator motor operates as the electric generator, as an allowable discharged quantity of the electric energy storage device when the generator motor operates as the electric motor, and limits an integrated discharged quantity which represents an integrated value of electric energy quantity discharged from the electric energy storage device when the generator motor operates as the electric motor, within the allowable discharged quantity. The control system also corrects the allowable discharged quantity depending on the electric energy quantity stored by the electric energy storage device when the generator motor starts operating as the electric motor.

Claims

1. A control system for controlling a hybrid vehicle having an engine as a propulsive power unit for the hybrid vehicle, an electric energy storage device for storing electric energy, and a generator motor operable alternatively as an electric motor for generating an assistive output power to be added to an output power generated by the engine, from the electric energy stored by the electric energy storage device, and as an electric generator for regenerating electric energy to be charged into the electric energy storage device, comprising:

control means for regarding an integrated charged quantity which represents an integrated value of electric energy quantity charged from the generator motor into the electric energy storage device when the generator motor operates as the electric generator, as an allowable discharged quantity of the electric energy storage device when the generator motor operates as the electric motor, and limiting an integrated discharged quantity which represents an integrated value of electric energy quantity discharged from the electric energy storage device when the generator motor operates as the electric motor, within said allowable discharged quantity; and

allowable discharged quantity correcting means for correcting said allowable discharged quantity depending on the electric energy quantity stored by the electric energy storage device when the generator motor starts operating as the electric motor.

2. A control system according to claim 1, wherein said allowable discharged quantity correcting means comprises means for correcting said allowable discharged quantity so as to increase by a corrective quantity if the electric energy quantity stored by the electric energy storage device is greater than a predetermined value.

3. A control system according to claim 2, wherein said allowable discharged quantity correcting means comprises means for increasing said corrective quantity as the electric energy quantity stored by the electric energy storage device is greater.

4. A control system according to any one of claims 1 through 3, wherein said integrated discharged quantity represents an integrated value electric energy quantities discharged from the electric energy storage device in respective operations of the generator motor as the electric motor, and each time the generator motor operates as the electric motor, said integrated charged quantity is updated to a value produced by subtracting the integrated discharged quantity determined when the generator motor operates as the electric motor from the integrated charged quantity when the generator motor starts operating as the electric motor.

5. A control system according to claim 1, wherein said control means comprises means for limiting said integrated discharged quantity within said allowable discharged quantity by canceling the operation of the generator motor as the electric motor when said integrated discharged quantity reaches said allowable discharged quantity while the generator motor is operating as the electric motor.

6. A control system according to claim 1, wherein said generator motor operates as the electric generator when the hybrid vehicle is decelerating or cruising and operates as the electric motor when the hybrid vehicle is accelerating.

7. A control system according to claim 1, wherein said electric energy storage device comprises an electric double-layer capacitor.