Vehicle Lock-Up Clutch Control Device for Accurate Learning

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Solution Overview

Problem

Conventional vehicle lock-up clutch control devices face issues with erroneous learning and loss of learning opportunities due to slip occurrences caused by engine auxiliary equipment load interventions during coasting capacity learning control, leading to incorrect lock-up differential pressure learning values and incomplete learning processes.

Innovation Solution

A lock-up clutch control device that generates a command value to decrease the lock-up engaging force during accelerator release, with a coasting capacity learning control section that updates the command value upon slip detection and corrects it with a lock-up pressure correction value when engine auxiliary equipment load intervenes, preventing slip and ensuring accurate learning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If coasting capacity learning control is performed by gradually decreasing lock-up clutch engaging capacity, then learning of lock-up differential pressure can be achieved, but slip of lock-up clutch occurs when engine auxiliary equipment load intervenes, causing erroneous learning

Engineering Contradiction:

Improvelock-up differential pressure learning value accuracyVSAvoidlearning control reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The control device performs preliminary detection of engine auxiliary equipment load intervention before slip occurs. When load intervention is detected, the control device preemptively adjusts the lock-up clutch engaging capacity or terminates the learning control, preventing slip from occurring in the first place and avoiding erroneous learning values.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control device continuously monitors operating parameters during coasting capacity learning control to detect engine auxiliary equipment load intervention. Based on this feedback, the control device dynamically adjusts the learning control process, either by modifying engaging capacity or terminating learning, thereby preventing slip and ensuring accurate learning.

Inventive Principle:

Principle #23Feedback

2Productivity

If slip occurrence is set as completion condition for learning control, then learning can be completed, but erroneous learning value is obtained when slip is caused by engine auxiliary equipment load

Engineering Contradiction:

Improvelearning control completion efficiencyVSAvoidlock-up differential pressure learning value accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Inventive Principle:

Principle #23Feedback

3Reliability

If variation of input torque is set as completion condition for learning control, then loss of learning opportunities is prevented, but learning cannot be completed when torque variation is caused by engine auxiliary equipment load

Engineering Contradiction:

Improvelearning control completion reliabilityVSAvoidlearning control completion rate

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The control device introduces an intermediary detection mechanism that distinguishes between torque variation caused by slip and torque variation caused by engine auxiliary equipment load. By detecting the specific cause of torque variation, the control device can determine whether to complete learning or continue, preventing both premature completion and unnecessary continuation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

Inventive Principle:

Principle #23Feedback

4Power

If engine auxiliary equipment load intervenes during coasting capacity learning control, then additional torque is input to lock-up clutch, but this causes slip in slight lockup state and prevents accurate learning

Engineering Contradiction:

Improveinput torque to lock-up clutchVSAvoidclutch engagement stability

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The control device performs preliminary detection of engine auxiliary equipment load intervention and applies counter-action by adjusting the lock-up clutch engaging capacity or terminating learning control before slip occurs. This preliminary anti-action prevents the harmful effect of load intervention from manifesting as clutch slip.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS10801613B2Vehicle lock-up clutch control device

Publication Date: 2020.10.13 JATCO LTD

AI summary

Provided is a lock-up clutch control device of a vehicle in which a torque converter with a lock-up clutch is disposed between an engine and a transmission. This control device has a coasting capacity learning control section configured to decrease a LU differential pressure command value for the lock-up clutch during accelerator release operation and, when a slip of the lock-up clutch is detected during decrease of the LU differential pressure command value, update the LU differential pressure command value at the time of detection of the slip as a LU differential pressure learning value balanced with a coasting torque. The coasting capacity learning control section is further configured to, when operation of the PTC heater intervenes during coasting capacity learning control, correct the LU differential pressure command value by adding thereto a LU differential pressure correction value that corresponds to an increase of input torque to the lock-up clutch.