Control system for hybrid vehicle

• US 6,314,346 B1
• Filed: 12/03/1999
• Issued: 11/06/2001
• Est. Priority Date: 12/07/1998
• 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: Uchida, Keisuke, Izumiura, Atsushi, Kitajima, Shinichi, Kumagai, Katsuhiro, Ukai, Asao, Fukuchi, Hironao
• Primary Examiner(s): Beaulieu, Yonel
• Application Number:
  US09/453,543
• Time in Patent Office: 704 Days
• Field of Search: 701/22, 320/103, 320/104, 320/121, 320/123, 320/132, 180/65.1, 180/65.2, 180/65.3, 290/7, 290/16, 290/50
• US Class Current: 701/22
• CPC Class Codes: B60K 6/28 characterised by the electric energy storing means, e.g. batteries or capacitors
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60K 6/543 the transmission being a continuously variable transmission
• CPC Class Codes: B60L 58/10 for monitoring or controlling batteries
• 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 2710/0622 Air-fuel ratio
• CPC Class Codes: B60W 2710/244 Charge state
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/14 for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle
• 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: Y10S 903/903 having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/918 Continuously variable
• CPC Class Codes: Y10S 903/919 Stepped shift

Abstract

A control system for a hybrid vehicle with an engine for producing a driving force for the vehicle, a motor for producing an assist driving force to assist the output from the engine, and a power storage unit for supplying electric energy to the motor and storing regenerated energy produced by regeneration of the motor when the vehicle decelerates. The control system includes a charge zone determining device for determining whether a state of charge (SOC) is within the normal use range, temporary use range, over-discharge range, or over-charge range; a generation mode selector for selecting one of a normal generation mode corresponding to normal use zone, a low generation mode corresponding to temporary use zone, a high generation mode corresponding to over-discharge zone, and a generation stop mode corresponding to over-charge zone, based on the determination by the charge zone determining device; and a generation amount setter for setting the amount of electric power generation corresponding to each mode.

Claims

1. A control system for a hybrid vehicle with an engine for producing a driving force for said vehicle, a motor for producing an assist driving force to assist the output from said engine, and a power storage unit for supplying electric energy to said motor and storing regenerated energy produced by regeneration of said motor when said vehicle decelerates, said control system comprising:

a charge zone determining device for determining whether a state of charge is within a normal use zone;

a temporary use zone;

an over-discharge zone, or an over-charge zone;

a generation mode selector for selecting one of a normal generation mode corresponding to said normal use zone, a low generation mode corresponding to said temporary use zone, a high generation mode corresponding to said over-discharge zone, and a generation stop mode corresponding to said over-charge zone, based on the determination by said charge zone determining device; and

a generation amount setter for setting the amount of electric power generation corresponding to each mode.

2. A system according to claim 1, further comprising:

a DOD limit determining device for determining whether the vehicle is in a depth-of-discharge limit control mode, in which said power storage unit is charged to recover the initial state of charge, which was detected at the starting of said vehicle, when the remaining charge is decreased from the initial state of charge by a predetermined amount,

wherein, when said DOD limit determining device determines that the vehicle is in the depth-of-discharge limit control mode, said generation mode selector selects a DOD limit generation mode, and said generation amount setter sets the amount of generation corresponding to the DOD limit generation mode.

3. A system according to claim 2, wherein the electric power generation set by said generation amount setter has the relationship of:

the electric power generated in the high generation mode>

the electric power generated in the low generation mode≧

the electric power generated in the DOD limit generation mode>

the electric power generated in the normal generation mode>

the electric power generated in the generation stop mode=0.

4. A system according to any one of claims 1 to 3, further comprising:

a lean-burn mode determining device for determining whether the vehicle is in the lean-burn mode in which the engine is driven at an air fuel ratio greater than the theoretical air-fuel ratio,

wherein, when said lean-burn mode determining device determines that the vehicle in the lean-burn mode, the amount of electric power generation set by said generation amount setter is decreased.

5. A system according to claim 4, wherein, when said charge zone determining device determines that the power storage unit is in the over-discharge zone, the entry into the lean-burn mode is prohibited.