Hybrid vehicle control device

Patent metadata

Field	Value
Publication number	US-10131345-B2
Application number	US-201314654077-A
Country	US
Kind code	B2
Filing date	Dec 20, 2013
Priority date	Dec 25, 2012
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

An object of the invention is to provide a hybrid vehicle control device capable of shortening the time from an engine start request to the engine start. The hybrid vehicle control device is provided with an integrated controller configured to execute processing for starting an engine by bringing a first clutch into engagement, while slipping a second clutch, and by increasing a torque of a motor generator, when it has been determined that an engine start request is present, and a first clutch engagement control section, which is included in the integrated controller and configured to command a start of engagement of the first clutch once the difference between the torque of the motor generator and a second clutch transmitted torque capacity command value becomes greater than or equal to a preset slip prediction determination threshold value after having been determined that the engine start request is present.

First claim

The invention claimed is:

1. A hybrid vehicle control device comprising:
an engine and a motor both serving as a driving power source of a vehicle;
a first clutch arranged in a power-train system of the driving power source to drive road wheels, the first clutch being interposed between the engine and the motor for varying a transmitted torque capacity between both the engine and the motor;
a second clutch arranged in the power-train system, the second clutch being interposed between the motor and the drive road wheels for varying a transmitted torque capacity between both the motor and the drive road wheels; and
a controller;
wherein the controller is configured to start the engine by bringing the first clutch into engagement, while slipping the second clutch, and by increasing a driving torque of the motor, when it has been determined that an engine start request is present, in an electric vehicle driving (EV) mode that enables the vehicle to run by the driving torque of the motor with the first clutch disengaged and with the second clutch engaged,
wherein the controller is further configured to command a start of engagement of the first clutch once a first-out engagement-start command condition, in which a difference between the driving torque of the motor and a transmitted torque capacity of the second clutch becomes greater than or equal to a preset slip prediction determination threshold value after it has been determined that the engine start request is present, is satisfied, and
wherein the slip prediction determination threshold value is preset such that a period of time required to bring the second clutch into a slip state from a time when the difference between the driving torque of the motor and the transmitted torque capacity of the second clutch exceeds the slip prediction determination threshold value is identical to a period of time required to bring the first clutch into an engagement state from a time when an engagement command is outputted to the first clutch.

2. A hybrid vehicle control device as recited in claim 1 , wherein:
the controller is further configured to set the first-out engagement-start command condition as a specific condition where a state that the difference exceeds the slip prediction determination threshold value has continued until a preset first-out determination time has expired.

3. A hybrid vehicle control device as recited in claim 2 , wherein:
the controller is further configured to set the first-out determination time based on a temperature of hydraulic oil used to engage the second clutch.

4. A hybrid vehicle control device as recited in claim 1 , wherein:
the controller is further configured to make a determination as to whether the second clutch is actually slipping, regardless of whether the first-out engagement-start command condition is satisfied or unsatisfied, when a preset slip prediction limit condition of the controller for limiting slip prediction is satisfied, and
the controller is further configured to command, based on the determination of the second clutch actually slipping, the start of engagement of the first clutch.

5. A hybrid vehicle control device as recited in claim 4 , wherein the slip prediction limit condition of the controller includes at least one of:
a situation where a temperature of hydraulic oil used for engagement of both the first and second clutches is less than or equal to a preset temperature at which a delay in engagement is predicted,
a situation where an accelerator operation amount is less than a preset value at which the slip of the second clutch hardly occurs,
a situation where the motor is kept in an output limit state in which the motor cannot output the motor torque of such magnitude as to cause the slip of the second clutch, and
a situation where a temperature of water for an inverter is less than or equal to a preset temperature value at which a preset output cannot be produced by the motor.

6. An engine start control method of a hybrid vehicle employing an engine and a motor both serving as a driving power source of a vehicle, a first clutch arranged in a power-train system of the driving power source to drive road wheels, the first clutch being interposed between the engine and the motor for varying a transmitted torque capacity between both the engine and the motor, and a second clutch arranged in the power-train system, the second clutch being interposed between the motor and the drive road wheels for varying a transmitted torque capacity between both the motor and the drive road wheels, the method comprising:
starting the engine by bringing the first clutch into engagement, while slipping the second clutch, and by increasing a driving torque of the motor, when it has been determined that an engine start request is present, in an electric vehicle driving (EV) mode that enables the vehicle to run by the driving torque of the motor with the first clutch disengaged and with the second clutch engaged; and
commanding a start of engagement of the first clutch once a first-out engagement-start command condition, in which a difference between the driving torque of the motor and a transmitted torque capacity of the second clutch becomes greater than or equal to a preset slip prediction determination threshold value after it has been determined that the engine start request is present, is satisfied,
wherein the slip prediction determination threshold value is preset such that a period of time required to bring the second clutch into a slip state from a time when the difference between the driving torque of the motor and the transmitted torque capacity of the second clutch exceeds the slip prediction determination threshold value is identical to a period of time required to bring the first clutch into an engagement state from a time when an engagement command is outputted to the first clutch.

Assignees

• Nissan Motor

Inventors

• Matsui Hiroki
• Shimoyama Hiroki

Classifications

• Y02T10/645

  Cross-Sectional Technologies · mapped topic

• F16D2500/70456

  Engine speed change rate · CPC title

• F16D2500/30421

  Torque of the output shaft · CPC title

• B60W2710/021

  Clutch engagement state · CPC title

• B60W10/02

  including control of driveline clutches · CPC title