Hybrid Vehicle Control Device Engine Start Timing

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Solution Overview

Problem

In hybrid vehicles, a delay in slip start timing of the second clutch occurs due to response delays in hydraulic control, leading to a time delay from engine start request to engine start.

Innovation Solution

A hybrid vehicle control device that commands the start of the first clutch engagement once the difference between the motor torque and the transmitted torque capacity of the second clutch exceeds a preset slip prediction determination threshold value, allowing earlier engagement of the first clutch.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a preset stand-by time is set from engine start request to first clutch engagement, then gear rattling is suppressed, but time delay from engine start request to engine start occurs

Engineering Contradiction:

Improvegear rattling suppressionVSAvoidtime delay from engine start request to engine start

Core Design Contradiction:

Stability of the object's compositionVSLoss of time

Solution Approach 1:

The system performs preliminary action by detecting the difference between motor torque and second clutch transmitted torque capacity before the second clutch actually slips. When this difference exceeds a threshold, the first clutch engagement is commanded in advance, before the preset stand-by time expires. This anticipatory engagement suppresses gear rattling while reducing the overall time delay from engine start request to engine start.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback by continuously monitoring the difference between motor torque and second clutch transmitted torque capacity. This real-time feedback allows the control device to dynamically determine when to command first clutch engagement based on actual torque conditions rather than relying solely on a fixed stand-by time, thereby optimizing both gear rattling suppression and start timing.

Inventive Principle:

Principle #23Feedback

2Reliability

If the second clutch is brought into slip with hydraulic control, then torque transmission is enabled, but response delay occurs in slip start timing

Engineering Contradiction:

Improvetorque transmissionVSAvoidslip start timing response speed

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The system performs preliminary detection of slip conditions by monitoring the difference between motor torque and second clutch transmitted torque capacity. When this difference exceeds a threshold, the first clutch engagement is commanded in advance, compensating for the inherent hydraulic response delay of the second clutch. This ensures reliable torque transmission while improving slip start timing response.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS10131345B2Hybrid vehicle control device

Publication Date: 2018.11.20 NISSAN MOTOR CO LTD

AI summary

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.