HYBRID VEHICLE CONTROL APPARATUS

• US 20080017427A1
• Filed: 07/20/2007
• Published: 01/24/2008
• Est. Priority Date: 07/21/2006
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: NAKANOWATARI, Jun
• Granted Patent: US 7,690,457 B2
• Time in Patent Office: Days
• US Class Current: 180/65.2
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• 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 10/115 with planetary gears
• 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 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 2710/025 Clutch slip, i.e. difference between input and output speeds
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/914 Actuated, e.g. engaged or disengaged by electrical, hydraulic or mechanical means

Abstract

A hybrid vehicle control apparatus includes an engine, a motor, first and second engaging elements, an input rotational speed and a controller. The first engaging element is arranged between the engine and the motor to selectively connect and disconnect the engine and the motor. The second engaging element is arranged between the motor and a drive wheel to selectively connect and disconnect the motor and the drive wheel. The input rotational speed detecting section is configured to detect an input rotational speed of the second engaging element corresponding to a rotational speed of the motor. The controller is configured to determine whether the second engaging element is seized based on the input rotational speed when a disengagement command or a slip engagement command has been issued to the second engaging element and a drive force of at least one of the engine and the motor has been changed.

Claims

1. A hybrid vehicle control apparatus comprising:

an engine;

a motor;

a first engaging element arranged between the engine and the motor to selectively connect and disconnect the engine and the motor;

a second engaging element arranged between the motor and a drive wheel of a vehicle to selectively connect and disconnect the motor and the drive wheel;

an input rotational speed detecting section configured and arranged to detect an input rotational speed of the second engaging element corresponding to a rotational speed of the motor; and

a controller configured to determine whether the second engaging element is seized based on the input rotational speed detected by the rotational speed detecting section when one of a disengagement command and a slip engagement command has been issued to the second engaging element and a drive force of at least one of the engine and the motor has been changed.

2. The hybrid vehicle control apparatus of claim 1, further comprising

an output rotational speed detecting section configured and arranged to detect an output rotational speed of the second engaging element corresponding to a rotational speed of the drive wheel, and

an automatic transmission having a plurality of planetary gears and a plurality of engaging elements including the second engaging element as at least one of the engaging elements, the automatic transmission being configured and arranged to achieve one of a plurality of gear ratios by selectively engaging and disengaging the engaging elements,

the controller being further configured to

determine a reference gear ratio that the automatic transmission achieves when the second engaging element is completely engaged,

calculate an actual gear ratio based on a ratio of the input rotational speed and the output rotational speed, and

determine that the second engaging element is seized if the actual gear ratio is within a prescribed range of error with respect to the reference gear ratio when the one of the disengagement command and the slip engagement command is issued to the second engaging element and the drive force of at least one of the engine and the motor is changed.

3. The hybrid vehicle control apparatus of claim 2, wherein

the controller is further configured to perform a determination control for determining whether the second engaging element is seized when the actual gear ratio calculated when the second engaging element is completely engaged is within the prescribed range of error with respect to the reference gear ratio.

4. The hybrid vehicle control apparatus of claim 1, wherein

the controller is further configured to determine whether the second engaging element is seized when the one of the disengagement command and the slip engagement command is issued to the second engaging element and the drive force of the at least one of the engine and the motor is increased while the vehicle is in a drive state.

5. The hybrid vehicle control apparatus of claim 1, wherein

the controller is further configured to determine whether the second engaging element is seized when the one of the disengagement command and the slip engagement command is issued to the second engaging element and the drive force of the at least one of the engine and the motor is decreased while the vehicle is in a coasting state.

6. The hybrid vehicle control apparatus of claim 1, further comprising

an automatic transmission having a plurality of planetary gears and a plurality of engaging elements including the second engaging element as at least one of the engaging elements, the automatic transmission being configured and arranged to achieve one of a plurality of gear ratios by selectively engaging and disengaging the engaging elements,

the second engaging element including a first brake element and a second brake element configured and arranged to transfer power in response to an inputted drive force by bearing a reaction force exerted by a rotary element coupled to an output shaft of the automatic transmission, the first brake element being coupled to the rotary element with a one-way clutch disposed therebetween and the second brake element being arranged in parallel with the first brake element,

the controller being further configured to

determine whether the first brake element of the second engaging element is seized when the one of the disengagement command and the slip engagement command is issued to the second engaging element and the drive force of the at least one of the engine and the motor is increased while the vehicle is in a drive state in which the first brake element is engaged and the second brake element is not engaged, and

determine whether the second brake element of the second engaging element is seized when the one of the disengagement command and the slip engagement command is issued to the second engaging element and the drive force of the at least one of the engine and the motor is decreased while the vehicle is in a coasting state in which the second brake is engaged.

7. The hybrid vehicle control apparatus of claim 6, wherein

the controller is further configured to determine a reference gear ratio that the automatic transmission achieves when the second engaging element is completely engaged, and to determine that the second engaging element is seized when a first actual gear ratio calculated when the second engaging element is completely engaged and a second actual gear ratio calculated when the one of the disengagement command and the slip engagement command is issued to the second engaging element are within a prescribed range of error with respect to the reference gear ratio.

8. The hybrid vehicle control apparatus of claim 1, wherein

the controller is further configured to start the engine by increasing the drive force of the motor and engaging the first engaging element when the vehicle is in a motor drive mode in which the engine is stopped, the first engaging element is disengaged, and the vehicle is traveling solely by the drive force of the motor, and to suppress an increase in the drive force of the motor until engagement of the first engaging element is started when the controller determines that the second engaging element is seized.

9. The hybrid vehicle control apparatus of claim 1, wherein

the controller is further configured to disengage the first engaging element when the controller determines that the second engaging element is seized and when the vehicle is traveling at or below a prescribed speed in a hybrid drive mode in which the engine is driven and the first engaging element is engaged.

10. A hybrid vehicle control apparatus comprising:

first drive force generating means for generating a first drive force;

second drive force generating means for generating a second drive force;

first engaging means for selectively engaging and disengaging the first and second drive force generating means;

second engaging means for selectively engaging and disengaging the second drive force generating means and a drive wheel of a vehicle;

input rotational speed detecting means for detecting an input rotational speed of the second engaging means corresponding to a rotational speed of the second drive force generating means; and

control means for determining whether the second engaging means is seized based on the input rotational speed detected by the rotational speed detecting means when the second engaging means is in one of a disengagement state and a slip engagement state and at least one of the first and second drive forces has been changed.

11. A hybrid vehicle control method comprising:

controlling a first engaging element disposed between an engine and a motor to selectively control a engagement state between the engine and the motor;

controlling a second engaging element disposed between the motor and a drive wheel of a vehicle to selectively control a engagement state between the motor and the drive wheel;

detecting an input rotational speed of the second engaging element corresponding to a rotational speed of the motor; and

determining whether the second engaging element is seized based on the input rotational speed detected when one of a disengagement command and a slip engagement command has been issued to the second engaging element and a drive force of at least one of the engine and the motor has been changed.