Hybrid vehicle employing hybrid system

• US 20030173123A1
• Filed: 02/14/2003
• Published: 09/18/2003
• Est. Priority Date: 03/18/2002
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Nakanowatari, Jun
• Granted Patent: US 6,962,224 B2
• Time in Patent Office: Days
• US Class Current: 180/65.2
• CPC Class Codes: B60K 6/44 Series-parallel type
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60L 3/0023 Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• 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 2510/068 Engine exhaust temperature
• CPC Class Codes: F02D 2200/0802 Temperature of the exhaust gas treatment apparatus
• CPC Class Codes: F02D 2200/1015 Engines misfires
• CPC Class Codes: F02D 41/042 for stopping the engine
• 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

Abstract

In a hybrid electric vehicle (HEV) employing a hybrid system using both an internal combustion engine and a second motor/generator as a propelling power source for vehicle propulsion, and also employing a first generator driven by the engine for power generation, an integrated HEV control system is provided to control the engine, and the first and second motor/generators. The integrated HEV control system permits operation of only the second motor/generator as the propelling power source to establish a motor propelled vehicle driving mode and simultaneously basically inhibits operation of the engine, when satisfying at least a condition that the engine misfire occurs. If a power generation requirement or a battery recharge requirement is present during the misfire period, operation of the engine is temporarily permitted for driving the first motor/generator only for a battery recharge.

Claims

1. A hybrid vehicle comprising:

an internal combustion engine serving as a propelling power source for vehicle propulsion;

an electric motor serving as a propelling power source for vehicle propulsion;

an electric generator driven by the engine for power generation;

a battery electrically connected to the motor and the generator;

sensors and switches for detecting operating conditions on the engine and the vehicle; and

a control system electrically connected to the engine, the motor, the generator, the battery and the sensors and switches, for controlling the engine, the motor and the generator;

the control system comprising;

(i) an engine misfire determination section that determines whether an engine misfire occurs; and

(ii) a control section that permits operation of only the motor as the propelling power source to establish a motor propelled vehicle driving mode and simultaneously inhibits operation of the engine, when satisfying a predetermined first condition comprising at least a condition that the engine misfire occurs.

2. The hybrid vehicle as claimed in claim 1, wherein:

the predetermined first condition comprises a condition that a state of charge of the battery is greater than or equal to a predetermined reference value.

3. The hybrid vehicle as claimed in claim 2, wherein:

the control section permits operation of the motor as the propelling power source to establish the motor propelled vehicle driving mode and simultaneously permits operation of the engine for driving the generator only for a battery recharge, when satisfying a predetermined second condition comprising a condition that the engine misfire occurs and a condition that the state of charge of the battery is less than the predetermined reference value.

4. The hybrid vehicle as claimed in claim 3, wherein:

the control section sets an operating range of the engine depending on a misfire rate of the engine when satisfying the predetermined second condition.

5. The hybrid vehicle as claimed in claim 4, wherein:

the control section sets a target engine speed of the engine operating range to a misfire-period maximum possible rotational speed existing within a limited range that at least a generated efficiency of the generator is greater than or equal to a predetermined generated efficiency.

6. The hybrid vehicle as claimed in claim 4, wherein:

the control section sets a target engine speed of the engine operating range to a misfire-period maximum possible rotational speed existing within a limited range that a generated efficiency of the generator is greater than or equal to a predetermined generated efficiency and a generated energy of the generator is greater than or equal to a predetermined generated energy.

7. The hybrid vehicle as claimed in claim 1, wherein:

the control section forcibly inhibits operation of the engine when satisfying a predetermined third condition comprising a condition that the engine misfire occurs and a condition that a catalyst temperature exceeds a predetermined temperature value.

8. The hybrid vehicle as claimed in claim 1, wherein:

the engine adapted to drive main drive wheels of the vehicle; and

the motor adapted to drive auxiliary drive wheels of the vehicle;

which further comprises;

a clutch element that connects and disconnects the main drive wheels to and from each of the engine and the generator.

9. A hybrid vehicle comprising:

an internal combustion engine serving as a propelling power source for vehicle propulsion;

an electric motor serving as a propelling power source for vehicle propulsion;

an electric generator driven by the engine for power generation;

a battery electrically connected to the motor and the generator;

sensors and switches for detecting operating conditions on the engine and the vehicle; and

a control system electrically connected to the engine, the motor, the generator, the battery and the sensors and switches, for controlling the engine, the motor and the generator;

the control system comprising;

(i) engine misfire determination means for determining whether an engine misfire occurs; and

(ii) control means for permitting operation of only the motor as the propelling power source to establish a motor propelled vehicle driving mode and simultaneously for inhibiting operation of the engine, when satisfying a predetermined first condition comprising at least a condition that the engine misfire occurs.

10. A method of controlling a hybrid vehicle employing an internal combustion engine serving as a propelling power source for vehicle propulsion, an electric motor serving as a propelling power source for vehicle propulsion, an electric generator driven by the engine for power generation, a battery electrically connected to the motor and the generator, and sensors and switches for detecting operating conditions on the engine and the vehicle, the method comprising:

determining whether an engine misfire occurs;

permitting operation of only the motor as the propelling power source to establish a motor propelled vehicle driving mode when satisfying at least a condition that the engine misfire occurs; and

simultaneously inhibiting operation of the engine, when satisfying the condition that the engine misfire occurs.

11. The method as claimed in claim 10, further comprising:

determining whether a power generation requirement for the generator is present;

permitting operation of the motor as the propelling power source to establish the motor propelled vehicle driving mode and operation of the engine for driving the generator only for a battery recharge, when satisfying the condition that the engine misfire occurs and a condition that the power generation requirement for the generator is present; and

setting both a target engine speed and a target engine torque based on a misfire rate of the engine when satisfying the condition that the engine misfire occurs and the condition that the power generation requirement for the generator is present.

12. The method as claimed in claim 11, further comprising:

setting the target engine speed to a misfire-period maximum possible rotational speed existing within a limited range that a generated efficiency of the generator is greater than or equal to a predetermined generated efficiency and a generated energy of the generator is greater than or equal to a predetermined generated energy.

13. The method as claimed in claim 12, further comprising:

forcibly inhibiting operation of the engine when satisfying the condition that the engine misfire occurs and a condition that a catalyst temperature exceeds a predetermined temperature value.