CONTROL APPARATUS AND CONTROL METHOD FOR HYBRID VEHICLE

• US 20100044131A1
• Filed: 08/13/2009
• Published: 02/25/2010
• Est. Priority Date: 08/25/2008
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Teraya, Ryuta
• Granted Patent: US 8,631,887 B2
• Time in Patent Office: Days
• US Class Current: 180/65.265
• CPC Class Codes: B60K 6/28 characterised by the electric energy storing means, e.g. batteries or capacitors
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 2240/445 Temperature
• 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 2510/0676 Engine temperature
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2510/246 Temperature
• CPC Class Codes: F02D 41/1495 Detection of abnormalities in the air/fuel ratio feedback system
• CPC Class Codes: F02N 11/0818 Conditions for starting or stopping the engine or for deactivating the idle-start-stop mode
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/93 Conjoint control of different elements

Abstract

A vehicle includes a charging unit for externally charging a power storage unit with electric power received from an external power supply, and an electric power generation unit capable of generating electric power from drive force received from an engine. The power storage unit is configured to be internally chargeable with electric power received from the electric power generation unit. The vehicle travels in selected one of EV priority mode restricting internal charging of the power storage unit and HV priority mode controlling internal charging such that a state of charge of the power storage unit is kept within a predetermined range. When a predetermined operating condition is satisfied while the vehicle is traveling, a control apparatus generates an operation request to the engine. The control apparatus changes the operating condition of the engine depending on whether the mode is EV priority mode or HV priority mode.

Claims

1. A control apparatus for a hybrid vehicle mounted with an internal combustion engine and an electric motor serving as a source of power for causing the vehicle to travel,

said hybrid vehicle including:

a chargeable and dischargeable power storage unit;

a charging unit for externally charging said power storage unit with electric power received from an external power supply, when said power storage unit is caused to enter a state chargeable by the external power supply; and

an electric power generation unit capable of generating electric power from drive force received from said internal combustion engine,

said electric motor generating drive force from electric power received from said power storage unit, and

said power storage unit being configured to be internally chargeable with electric power received from said electric power generation unit,

said control apparatus comprising;

a mode selection unit for selecting one of a first travel mode and a second travel mode for causing said vehicle to travel, said first travel mode restricting internal charging of said power storage unit by said electric power generation unit, and said second travel mode controlling internal charging of said power storage unit by said electric power generation unit such that a state of charge of said power storage unit is kept within a predetermined range;

an operation request generation unit for generating an operation request to said internal combustion engine when a predetermined operating condition is satisfied while said vehicle is traveling; and

an intermittent operation control unit for starting said internal combustion engine in response to said operation request and stopping said internal combustion engine in response to cancellation of said operation request,

said operation request generation unit changing said predetermined operating condition depending on whether said first travel mode is selected or said second travel mode is selected.

2. The control apparatus for a hybrid vehicle according to claim 1, wherein

said control apparatus further comprises a start preparation unit for preparing for start of said internal combustion engine by preheating a sensor provided to an exhaust system for said internal combustion engine, and

said operation request generation unit generates said operation request when preparation for start of said internal combustion engine is completed while said second travel mode is selected, and said operation request generation unit does not generate said operation request when preparation for start of said internal combustion engine is completed while said first travel mode is selected.

3. The control apparatus for a hybrid vehicle according to claim 1, wherein

said operation request generation unit generates said operation request when coolant temperature of said internal combustion engine is lower than a first threshold value while said first travel mode is selected, and generates said operation request when the coolant temperature of said internal combustion engine is lower than a second threshold value larger than said first threshold value while said second travel mode is selected.

4. The control apparatus for a hybrid vehicle according to claim 1, wherein

said control apparatus further comprises a calculation unit for calculating a cumulative intake air amount from the time when said internal combustion engine is started, and

said operation request generation unit generates said operation request when said cumulative intake air amount is less than a first reference amount while said first travel mode is selected, and generates said operation request when said cumulative intake air amount is less than a second reference amount larger than said first reference amount while said second travel mode is selected.

5. The control apparatus for a hybrid vehicle according to claim 1, wherein

said control apparatus further comprises a catalyst temperature obtaining unit for obtaining temperature of a catalyst capable of purifying exhaust gas discharged from said internal combustion engine, and

said operation request generation unit generates said operation request when the temperature of said catalyst is lower than a first allowable temperature while said first travel mode is selected, and generates said operation request when the temperature of said catalyst is lower than a second allowable temperature higher than said first allowable temperature while said second travel mode is selected.

6. The control apparatus for a hybrid vehicle according to claim 1, wherein

said control apparatus further comprises a catalyst warm-up unit for controlling said internal combustion engine such that a catalyst capable of purifying exhaust gas discharged from said internal combustion engine is warmed up, and

said operation request generation unit generates said operation request until catalyst warm-up duration from the time when said internal combustion engine is started becomes equal to a first specified time period while said first travel mode is selected, and generates said operation request until said catalyst warm-up duration becomes equal to a second specified time period longer than said first specified time period while said second travel mode is selected.

7. The control apparatus for a hybrid vehicle according to claim 1, wherein

said control apparatus further comprises a state estimation unit for estimating a state of charge of said power storage unit, and

said mode selection unit selects said first travel mode when said state of charge is not smaller than a predetermined value, and switches said first travel mode to said second travel mode when said state of charge becomes smaller than said predetermined value.

8. A control method for a hybrid vehicle mounted with an internal combustion engine and an electric motor serving as a source of power for causing the vehicle to travel,

said hybrid vehicle including:

a chargeable and dischargeable power storage unit;

a charging unit for externally charging said power storage unit with electric power received from an external power supply, when said power storage unit is caused to enter a state chargeable by the external power supply; and

an electric power generation unit capable of generating electric power from drive force received from said internal combustion engine,

said electric motor generating drive force from electric power received from said power storage unit, and

said power storage unit being configured to be internally chargeable with electric power received from said electric power generation unit,

said control method comprising the steps of;

selecting one of a first travel mode and a second travel mode for causing said vehicle to travel, said first travel mode restricting internal charging of said power storage unit by said electric power generation unit, and said second travel mode controlling internal charging of said power storage unit by said electric power generation unit such that a state of charge of said power storage unit is kept within a predetermined range;

generating an operation request to said internal combustion engine when a predetermined operating condition is satisfied while said vehicle is traveling; and

starting said internal combustion engine in response to said operation request and stopping said internal combustion engine in response to cancellation of said operation request,

said step of generating an operation request including changing said predetermined operating condition depending on whether said first travel mode is selected or said second travel mode is selected.

9. The control method for a hybrid vehicle according to claim 8, wherein

said control method further comprises the step of preparing for start of said internal combustion engine by preheating a sensor provided to an exhaust system for said internal combustion engine, and

said step of generating an operation request includes generating said operation request when preparation for start of said internal combustion engine is completed while said second travel mode is selected, and not generating said operation request when preparation for start of said internal combustion engine is completed while said first travel mode is selected.

10. The control method for a hybrid vehicle according to claim 8, wherein

said step of generating an operation request includes generating said operation request when coolant temperature of said internal combustion engine is lower than a first threshold value while said first travel mode is selected, and generating said operation request when the coolant temperature of said internal combustion engine is lower than a second threshold value larger than said first threshold value while said second travel mode is selected.

11. The control method for a hybrid vehicle according to claim 8, wherein

said control method further comprises the step of calculating a cumulative intake air amount from the time when said internal combustion engine is started, and

said step of generating an operation request includes generating said operation request when said cumulative intake air amount is less than a first reference amount while said first travel mode is selected, and generating said operation request when said cumulative intake air amount is less than a second reference amount larger than said first reference amount while said second travel mode is selected.

12. The control method for a hybrid vehicle according to claim 8, wherein

said control method further comprises the step of obtaining temperature of a catalyst capable of purifying exhaust gas discharged from said internal combustion engine, and

said step of generating an operation request includes generating said operation request when the temperature of said catalyst is lower than a first allowable temperature while said first travel mode is selected, and generating said operation request when the temperature of said catalyst is lower than a second allowable temperature higher than said first allowable temperature while said second travel mode is selected.

13. The control method for a hybrid vehicle according to claim 8, wherein

said control method further comprises the step of controlling said internal combustion engine such that a catalyst capable of purifying exhaust gas discharged from said internal combustion engine is warmed up, and

said step of generating an operation request includes generating said operation request until catalyst warm-up duration from the time when said internal combustion engine is started becomes equal to a first specified time period while said first travel mode is selected, and generating said operation request until said catalyst warm-up duration becomes equal to a second specified time period longer than said first specified time period while said second travel mode is selected.

14. The control method for a hybrid vehicle according to claim 8, wherein

said control method further comprises the step of estimating a state of charge of said power storage unit, and

said step of selecting one of a first travel mode and a second travel mode includes selecting said first travel mode when said state of charge is not smaller than a predetermined value, and switching said first travel mode to said second travel mode when said state of charge becomes smaller than said predetermined value.